Tidal acceleration is an effect of the tidal forces between an orbiting natural satellite (e.g. the Moon), and the primary planet that it orbits (e.g. the Earth). The "acceleration" is usually negative, as it causes a gradual slowing and recession of a satellite in a prograde orbit away from the primary, and a corresponding slowdown of the primary's rotation. The process eventually leads to tidal locking of first the smaller, and later the larger body. The Earth-Moon system is the best studied case.

The similar process of tidal deceleration occurs for satellites that have an orbital period that is shorter than the primary's rotation period, or that orbit in a retrograde direction.

Earth-Moon system

Discovery history of the secular acceleration

Edmond Halley was the first to suggest, in 1695, that the mean motion of the Moon was apparently getting faster, by comparison with ancient eclipse observations, but he gave no data. (It was not yet known in Halley's time that what is actually occurring includes a slowing-down of the Earth's rate of rotation: see also Ephemeris time - History. When measured as a function of mean solar time rather than uniform time, the effect appears as a positive acceleration.) In 1749 Richard Dunthorne confirmed Halley's suspicion after re-examining ancient records, and produced the first quantitative estimate for the size of this apparent effect: a centurial rate of +10" (arcseconds) in lunar longitude (a surprisingly good result for its time, not far different from values assessed later, e.g. in 1786 by de Lalande, and to compare with values from about 10" to nearly 13" being derived about century later.)

Pierre-Simon Laplace produced in 1786 a theoretical analysis giving a basis on which the Moon's mean motion should accelerate in response to perturbational changes in the eccentricity of the orbit of the Earth around the Sun. Laplace's initial computation accounted for the whole effect, thus seeming to tie up the theory neatly with both modern and ancient observations.

However, in 1854, J C Adams caused the question to be re-opened by finding an error in Laplace's computations: it turned out that only about half of the Moon's apparent acceleration could be accounted for on Laplace's basis by the change in the Earth's orbital eccentricity. Adams' finding provoked a sharp astronomical controversy that lasted some years, but the correctness of his result, agreed by other mathematical astronomers including C E Delaunay, was eventually accepted. The question depended on correct analysis of the lunar motions, and received a further complication with another discovery, around the same time, that another significant long-term perturbation that had been calculated for the Moon (supposedly due to the action of Venus) was also in error, was found on re-examination to be almost negligible, and practically had to disappear from the theory. A part of the answer was suggested independently in the 1860s by Delaunay and by William Ferrel: tidal retardation of the Earth's rotation rate was lengthening the unit of time and causing a lunar acceleration that was only apparent.

It took some time for the astronomical community to accept the reality and the scale of tidal effects. But eventually it became clear that three effects are involved, when measured in terms of mean solar time. Beside the effects of perturbational changes in the Earth's orbital eccentricity, as found by Laplace and corrected by Adams, there are two tidal effects (a combination first suggested by Emmanuel Liais). First there is a real retardation of the Moon's angular rate of orbital motion, due to tidal exchange of angular momentum between the Earth and Moon. This increases the Moon's angular momentum around the Earth (and moves the Moon to a higher orbit with a slower period). Secondly there is an apparent increase in the Moon's angular rate of orbital motion (when measured in terms of mean solar time). This arises from the Earth's loss of angular momentum and the consequent increase in length of day.

Effects of Moon's gravity

Because the Moon's mass is a considerable fraction of that of the Earth (about 1:81), the two bodies can be regarded as a double planet system, rather than as a planet with a satellite. The plane of the Moon's orbit around the Earth lies close to the plane of the Earth's orbit around the Sun (the ecliptic), rather than in the plane perpendicular to the axis of rotation of the Earth (the equator) as is usually the case with planetary satellites. The mass of the Moon is sufficiently large, and it is sufficiently close, to raise tides in the matter of the Earth. In particular, the water of the oceans bulges out along both ends of an axis passing through the centers of the Earth and Moon. The average tidal bulge closely follows the Moon in its orbit, and the Earth rotates under this tidal bulge in just over a day. However, the rotation drags the position of the tidal bulge ahead of the position directly under the Moon. As a consequence, there exists a substantial amount of mass in the bulge that is offset from the line through the centers of the Earth and Moon. Because of this offset, a portion of the gravitational pull between Earth's tidal bulges and the Moon is perpendicular to the Earth-Moon line, i.e. there exists a torque between the Earth and the Moon. This boosts the Moon in its orbit, and decelerates the rotation of the Earth.

So the result is that the mean solar day, which is nominally 86400 seconds long, is actually getting longer when measured in SI seconds with stable atomic clocks. (The SI second, when adopted, was already a little shorter than the current value of the second of mean solar time.) The small difference accumulates every day, which leads to an increasing difference between our clock time (Universal Time) on the one hand, and Atomic Time and Ephemeris Time on the other hand: see ΔT. This makes it necessary to insert a leap second at irregular intervals.

In addition to the effect of the ocean tides, there is also a tidal acceleration due to flexing of the earth's crust, but this accounts for only about 4% of the total effect when expressed in terms of heat dissipation.

If other effects were ignored, tidal acceleration would continue until the rotational period of the Earth matched the orbital period of the Moon. At that time, the Moon would always be overhead of a single fixed place on Earth. Such a situation already exists in the Pluto-Charon system. However, the slowdown of the Earth's rotation is not occurring fast enough for the rotation to lengthen to a month before other effects make this irrelevant: About 2.1 billion years from now, the continual increase of the Sun's radiation will cause the Earth's oceans to vaporize, removing the bulk of the tidal friction and acceleration. Even without this, the slowdown to a month-long day would still not have been completed by 4.5 billion years from now when the Sun will evolve into a red giant and possibly destroy both the Earth and Moon. (Tidal acceleration and solar mass loss is also moving the Earth outward from the Sun, but it is unknown whether it will be enough to save it from destruction.)

Tidal acceleration is one of the few examples in the dynamics of the solar system of a so-called secular perturbation of an orbit, i.e. a perturbation that continuously increases with time and is not periodic. Up to a high order of approximation, mutual gravitational perturbations between major or minor planets only cause periodic variations in their orbits, that is, parameters oscillate between maximum and minimum values. The tidal effect gives rise to a quadratic term in the equations, which leads to unbounded growth. In the mathematical theories of the planetary orbits that form the basis of ephemerides, quadratic and higher order secular terms do occur, but these are mostly Taylor expansions of very long time periodic terms. The reason that tidal effects are different is that unlike distant gravitational perturbations, friction is an essential part of tidal acceleration, and leads to permanent loss of energy from the dynamical system in the form of heat. In other words, we do not have a Hamiltonian system here.

Angular momentum and energy

The gravitational torque between the Moon and the tidal bulge of the Earth causes the Moon to be promoted in its orbit, and the Earth to be decelerated in its rotation. As in any physical process within an isolated system, total energy and angular momentum are conserved. Effectively, energy and angular momentum are transferred from the rotation of the Earth to the orbital motion of the Moon (however, most of the energy lost by the Earth is converted to heat, and only about one 30th is transferred to the Moon). The Moon moves farther away from the Earth, so its potential energy (in the Earth's gravity well) increases. It stays in orbit, and from Kepler's 3rd law it follows that its velocity actually decreases, so the tidal action on the Moon actually causes a deceleration of its motion across the celestial sphere. Although its kinetic energy decreases, its potential energy increases by a larger amount. The tidal force has a component in the direction of the Moon's motion, and therefore increases its energy, but the non-tidal part of the Earth's gravity pulls (on average) slightly backwards on the Moon (which on average has a slight outward velocity), so the net result is that the Moon slows down. The Moon's orbital angular momentum increases.

The rotational angular momentum of the Earth decreases and consequently the length of the day increases. The net tide raised on Earth by the Moon is dragged ahead of the Moon by Earth's much faster rotation. Tidal friction is required to drag and maintain the bulge ahead of the Moon, and it dissipates the excess energy of the exchange of rotational and orbital energy between the Earth and Moon as heat. If the friction and heat dissipation were not present, the Moon's gravitational force on the tidal bulge would rapidly (within two days) bring the tide back into synchronization with the Moon, and the Moon would no longer recede. Most of the dissipation occurs in a turbulent bottom boundary layer in shallow seas such as the European shelf around the British Isles, the Patagonian shelf off Argentina, and the Bering Sea.

The dissipation of energy by tidal friction averages about 3.75 terawatts, of which 2.5 terawatts are from the principal M lunar component and the remainder from other components, both lunar and solar.

An equilibrium tidal bulge does not really exist on Earth because the continents do not allow this mathematical solution to take place. Oceanic tides actually rotate around the oceans basin as vast gyres around several amphidromic points where no tide exists. The Moon pulls on each individual undulation as Earth rotates—some undulations are ahead of the Moon, others are behind it, while still others are on either side. The "bulges" that actually do exist for the Moon to pull on (and which pull on the Moon) are the net result of integrating the actual undulations over all the world's oceans. Earth's net (or equivalent) equilibrium tide has an amplitude of only 3.23 cm, which is totally swamped by oceanic tides that can exceed one metre.

Historical evidence

This mechanism has been working for 4.5 billion years, since oceans first formed on the Earth. There is geological and paleontological evidence that the Earth rotated faster and that the Moon was closer to the Earth in the remote past. Tidal rhythmites are alternating layers of sand and silt laid down offshore from estuaries having great tidal flows. Daily, monthly and seasonal cycles can be found in the deposits. This geological record is consistent with these conditions 620 million years ago: the day was 21.9±0.4 hours, and there were 13.1±0.1 synodic months/year and 400±7 solar days/year. The length of the year has remained virtually unchanged during this period because no evidence exists that the constant of gravitation has changed. The average recession rate of the Moon between then and now has been 2.17±0.31 cm/year, which is about half the present rate.

Quantitative description of the Earth-Moon case

The motion of the Moon can be followed with an accuracy of a few centimeters by lunar laser ranging (LLR). Laser pulses are bounced off mirrors on the surface of the moon, emplaced during the Apollo missions of 1969 to 1972 and by Lunokhod 2 in 1973. Measuring the return time of the pulse yields a very accurate measure of the distance. These measurements are fitted to the equations of motion. This yields numerical values for the Moon's secular acceleration in longitude and the rate of change of the semimajor axis of the Earth-Moon ellipse. From the period 1970–2007, the results are:

: −25.85"/cy² in ecliptic longitude : (cy is centuries, here taken to the square) : +38.14 mm/yr in the mean Earth-Moon distance

The other consequence of tidal acceleration is the deceleration of the rotation of the Earth. The rotation of the Earth is somewhat erratic on all time scales (from hours to centuries) due to various causes. The small tidal effect cannot be observed in a short period, but the cumulative effect on the Earth's rotation as measured with a stable clock (ephemeris time, atomic time) of a shortfall of even a few milliseconds every day becomes readily noticeable in a few centuries. Since some event in the remote past, more days and hours have passed (as measured in full rotations of the Earth) (Universal Time) than as measured with stable clocks calibrated to the present, longer length of the day (ephemeris time). This is known as ΔT. Recent values can be obtained from the International Earth Rotation and Reference Systems Service (IERS). A table of the actual length of the day in the past few centuries is also available.

From the observed change in the Moon's orbit, the corresponding change in the length of the day can be computed:

: +2.3 ms/cy

: (cy is centuries).

However, from historical records over the past 2700 years the following average value is found:

: +1.70 ± 0.05 ms/cy

The corresponding cumulative value is a parabola having a coefficient of T² (time in centuries squared) of:

: ΔT = +31 s/cy²

Opposing the tidal deceleration of the Earth is a mechanism that is in fact accelerating the rotation. The Earth is not a sphere, but rather an ellipsoid that is flattened at the poles. SLR has shown that this flattening is decreasing. The explanation is, that during the ice age large masses of ice collected at the poles, and depressed the underlying rocks. The ice mass started disappearing over 10000 years ago, but the Earth's crust is still not in hydrostatic equilibrium and is still rebounding (the relaxation time is estimated to be about 4000 years). As a consequence, the polar diameter of the Earth increases, and since the mass and density remain the same, the volume remains the same; therefore the equatorial diameter is decreasing. As a consequence, mass moves closer to the rotation axis of the Earth. This means that its moment of inertia is decreasing. Because its total angular momentum remains the same during this process, the rotation rate increases. This is the well-known phenomenon of a spinning figure skater who spins ever faster as she retracts her arms. From the observed change in the moment of inertia the acceleration of rotation can be computed: the average value over the historical period must have been about −0.6 ms/cy. This largely explains the historical observations.

Other cases of tidal acceleration

Most natural satellites of the planets undergo tidal acceleration to some degree (usually small), except for the two classes of tidally decelerated bodies. In most cases, however, the effect is small enough that even after billions of years most satellites will not actually be lost. The effect is probably most pronounced for Mars' second moon Deimos, which may become an Earth-crossing asteroid after it leaks out of Mars' grip . The effect also arises between different components in a binary star.

Tidal deceleration

This comes in two varieties: # Fast satellites: Some inner moons of the gas giant planets and Phobos orbit within the synchronous orbit radius so that their orbital period is shorter than their planet's rotation. In this case the tidal bulges raised by the moon on their planet lag behind the moon, and act to decelerate it in its orbit. The net effect is a decay of that moon's orbit as it gradually spirals towards the planet. The planet's rotation also speeds up slightly in the process. In the distant future these moons will impact the planet or cross within their Roche limit and be tidally disrupted into fragments. However, all such moons in the solar system are very small bodies and the tidal bulges raised by them on the planet are also small, so the effect is usually weak and the orbit decays slowly. The moons affected are: #*Around Mars: Phobos #*Around Jupiter: Metis and Adrastea #*Around Saturn: none, except for the ring particles (like Jupiter, Saturn is a very rapid rotator but has no satellites close enough) #*Around Uranus: Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Cupid, Belinda, and Perdita #*Around Neptune: Naiad, Thalassa, Despina, Galatea and Larissa # Retrograde satellites: All retrograde satellites experience tidal deceleration to some degree because the moon's orbital motion and the planet's rotation are in opposite directions, causing restoring forces from their tidal bulges. A difference to the previous "fast satellite" case here is that the planet's rotation is also slowed down rather than sped up (angular momentum is still conserved because in such a case the values for the planet's rotation and the moon's revolution have opposite signs). The only satellite in the Solar System for which this effect is non-negligible is Neptune's moon Triton. All the other retrograde satellites are on distant orbits and tidal forces between them and the planet are negligible. The planet Venus is believed to have no satellites chiefly because any hypothetical satellites would have suffered deceleration long ago, from either cause; Venus has a very slow and retrograde rotation.

See also

Tidal locking

Tidal force

Tides

Tidal heating

References

External links

The Recession of the Moon and the Age of the Earth-Moon System

Tidal Heating as Described by University of Washington Professor Toby Smith

Category:Tides Category:Geodesy Category:Celestial mechanics Category:Orbit of the Moon

Coordinates	41°52′55″N87°37′40″N
Conflict	World War I
Caption	Clockwise from top: Trenches on the Western Front; a British Mark IV Tank crossing a trench; Royal Navy battleship HMS Irresistible sinking after striking a mine at the Battle of the Dardanelles; a Vickers machine gun crew with gas masks, and German Albatros D.III biplanes
Date	28 July 1914 – 11 November 1918 (Armistice)
Place	Europe, Africa, the Middle East, the Pacific Islands, China and off the coast of South and North America
Casus	Assassination of Archduke Franz Ferdinand (28 June) followed by Austro-Hungarian declaration of war on Kingdom of Serbia (28 July) and Russian mobilisation against Austria–Hungary (29 July).
Result	Allied victory
Combatant1	Allied (Entente) Powers
Combatant2	Central Powers
Commander1	Leaders and commanders
Commander2	Leaders and commanders
Strength1	Allies
Strength2	Central Powers which were assembled in two opposing alliances: the Allies (centred around the Triple Entente) and the Central Powers (originally centered around the Triple Alliance). More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. More than 9 million combatants were killed, largely because of great technological advances in firepower without corresponding advances in mobility. It was the second deadliest conflict in Western history.

On the battle of the Menin Road Ridge, Ludendorff wrote, 's Bermuda Contingent, Royal Garrison Artillery, in Europe.]]

Around 1.1 to 1.2 million soldiers from the British and Dominion armies were on the Western Front at any one time. A thousand battalions, occupying sectors of the line from the North Sea to the Orne River, operated on a month-long four-stage rotation system, unless an offensive was underway. The front contained over of trenches. Each battalion held its sector for about a week before moving back to support lines and then further back to the reserve lines before a week out-of-line, often in the Poperinge or Amiens areas.

In the 1917 Battle of Arras, the only significant British military success was the capture of Vimy Ridge by the Canadian Corps under Sir Arthur Currie and Julian Byng. The assaulting troops were able for the first time to overrun, rapidly reinforce and hold the ridge defending the coal-rich Douai plain.

Naval war

making steam for Scapa Flow, 1914]] At the start of the war, the German Empire had cruisers scattered across the globe, some of which were subsequently used to attack Allied merchant shipping. The British Royal Navy systematically hunted them down, though not without some embarrassment from its inability to protect Allied shipping. For example, the German detached light cruiser SMS Emden, part of the East-Asia squadron stationed at Tsingtao, seized or destroyed 15 merchantmen, as well as sinking a Russian cruiser and a French destroyer. However, the bulk of the German East-Asia squadron—consisting of the armoured cruisers and , light cruisers and and two transport ships—did not have orders to raid shipping and was instead underway to Germany when it encountered elements of the British fleet. The German flotilla, along with , sank two armoured cruisers at the Battle of Coronel, but was almost destroyed at the Battle of the Falkland Islands in December 1914, with only Dresden and a few auxiliaries escaping, but at the Battle of Más a Tierra these too were destroyed or interned.

at sea]] Soon after the outbreak of hostilities, Britain initiated a naval blockade of Germany. The strategy proved effective, cutting off vital military and civilian supplies, although this blockade violated generally accepted international law codified by several international agreements of the past two centuries. Britain mined international waters to prevent any ships from entering entire sections of ocean, causing danger to even neutral ships. Since there was limited response to this tactic, Germany expected a similar response to its unrestricted submarine warfare.

The 1916 Battle of Jutland (German: Skagerrakschlacht, or "Battle of the Skagerrak") developed into the largest naval battle of the war, the only full-scale clash of battleships during the war, and one of the largest in history. It took place on 31 May – 1 June 1916, in the North Sea off Jutland. The Kaiserliche Marine's High Seas Fleet, commanded by Vice Admiral Reinhard Scheer, squared off against the Royal Navy's Grand Fleet, led by Admiral Sir John Jellicoe. The engagement was a stand off, as the Germans, outmanoeuvred by the larger British fleet, managed to escape and inflicted more damage to the British fleet than they received. Strategically, however, the British asserted their control of the sea, and the bulk of the German surface fleet remained confined to port for the duration of the war.

German U-boats attempted to cut the supply lines between North America and Britain. The nature of submarine warfare meant that attacks often came without warning, giving the crews of the merchant ships little hope of survival. The United States launched a protest, and Germany modified its rules of engagement. After the notorious sinking of the passenger ship RMS Lusitania in 1915, Germany promised not to target passenger liners, while Britain armed its merchant ships, placing them beyond the protection of the "cruiser rules" which demanded warning and placing crews in "a place of safety" (a standard which lifeboats did not meet). Finally, in early 1917 Germany adopted a policy of unrestricted submarine warfare, realising the Americans would eventually enter the war. Germany sought to strangle Allied sea lanes before the U.S. could transport a large army overseas, but were only able to maintain five long range U-boats on station, to limited effect. The U-boats had sunk more than 5,000 Allied ships, at a cost of 199 submarines.

World War I also saw the first use of aircraft carriers in combat, with HMS Furious launching Sopwith Camels in a successful raid against the Zeppelin hangars at Tondern in July 1918, as well as blimps for antisubmarine patrol.

Southern theatres

War in the Balkans

.]] Faced with Russia, Austria-Hungary could spare only one-third of its army to attack Serbia. After suffering heavy losses, the Austrians briefly occupied the Serbian capital, Belgrade. A Serbian counter attack in the battle of Kolubara, however, succeeded in driving them from the country by the end of 1914. For the first ten months of 1915, Austria-Hungary used most of its military reserves to fight Italy. German and Austro-Hungarian diplomats, however, scored a coup by persuading Bulgaria to join in attacking Serbia. The Austro-Hungarian provinces of Slovenia, Croatia and Bosnia provided troops for Austria-Hungary, invading Serbia as well as fighting Russia and Italy. Montenegro allied itself with Serbia.

Serbia was conquered in a little more than a month. The attack began in October, when the Central Powers launched an offensive from the north; four days later the Bulgarians joined the attack from the east. The Serbian army, fighting on two fronts and facing certain defeat, retreated into Albania, halting only once to make a stand against the Bulgarians. The Serbs suffered defeat near modern day Gnjilane in the Battle of Kosovo. Montenegro covered the Serbian retreat towards the Adriatic coast in the Battle of Mojkovac in 6–7 January 1916, but ultimately the Austrians conquered Montenegro, too. Serbian forces were evacuated by ship to Greece.

In late 1915, a Franco-British force landed at Salonica in Greece, to offer assistance and to pressure the government to declare war against the Central Powers. Unfortunately for the Allies, the pro-German King Constantine I dismissed the pro-Allied government of Eleftherios Venizelos, before the Allied expeditionary force could arrive. The friction between the king of Greece and the Allies continued to accumulate with the National Schism, which effectively divided Greece between regions still loyal to the king and the new provisional government of Venizelos located in Salonica. After intense diplomatic negotiations and an armed confrontation in Athens between Allied and royalist forces (an incident known as Noemvriana) the king of Greece resigned, and his second son Alexander took his place. Venizelos returned to Athens on 29 May 1917 and Greece, now unified, officially joined the war on the side of the Allies. The entire Greek army was mobilized and began to participate in military operations against the Central Powers on the Macedonian front. After conquest, Serbia was divided between Austro-Hungary and Bulgaria. Bulgarians commenced Bulgarization of the Serbian population in their occupation zone, banishing Serbian Cyrillic and the Serbian Orthodox Church. After forced conscription of the Serbian population into the Bulgarian army in 1917, the Toplica Uprising began. Serbian rebels liberated for a short time the area between the Kopaonik mountains and the South Morava river. The uprising was crushed by joint efforts of Bulgarian and Austrian forces at the end of March 1917.

The Macedonian Front proved static for the most part. Serbian forces retook part of Macedonia by recapturing Bitola on 19 November 1916. Only at the end of the conflict were the Entente powers able to break through, after most of the German and Austro-Hungarian troops had withdrawn. The Bulgarians suffered their only defeat of the war at the Battle of Dobro Pole but days later, they decisively defeated British and Greek forces at the Battle of Doiran, avoiding occupation. Bulgaria signed an armistice on 29 September 1918. Hindenburg and Ludendorff concluded that the strategic and operational balance had now shifted decidedly against the Central Powers and a day after the Bulgarian collapse, during a meeting with government officials, insisted on an immediate peace settlement.

The disappearance of the Macedonian front meant that the road to Budapest and Vienna was now opened for the 670,000-strong army of general Franchet d'Esperey as the Bulgarian capitulation deprived the Central Powers of the 278 infantry battalions and 1,500 guns (the equivalent of some 25 to 30 German divisions) that were previously holding the line.

Ottoman Empire

in the Battle of Jerusalem.]] The Ottoman Empire joined the Central Powers in the war, the secret Ottoman-German Alliance having been signed in August 1914. It threatened Russia's Caucasian territories and Britain's communications with India via the Suez Canal. The British and French opened overseas fronts with the Gallipoli (1915) and Mesopotamian campaigns. In Gallipoli, the Ottoman Empire successfully repelled the British, French and Australian and New Zealand Army Corps (ANZACs). In Mesopotamia, by contrast, after the disastrous Siege of Kut (1915–16), British Imperial forces reorganised and captured Baghdad in March 1917. Further to the west, in the Sinai and Palestine Campaign, initial British setbacks were overcome when they captured Jerusalem in December 1917. The Egyptian Expeditionary Force, under Field Marshal Edmund Allenby, broke the Ottoman forces at the Battle of Megiddo in September 1918.

Russian armies generally had the best of it in the Caucasus. Enver Pasha, supreme commander of the Ottoman armed forces, was ambitious and dreamed of re-conquering central Asia, and areas that had been lost to Russia previously. He was, however, a poor commander. He launched an offensive against the Russians in the Caucasus in December 1914 with 100,000 troops; insisting on a frontal attack against mountainous Russian positions in winter, he lost 86% of his force at the Battle of Sarikamish.

General Yudenich, the Russian commander from 1915 to 1916, drove the Turks out of most of the southern Caucasus with a string of victories.

Instigated by the Arab bureau of the British Foreign and Commonwealth Office, the Arab Revolt started with the help of Britain in June 1916 at the Battle of Mecca, led by Sherif Hussein of Mecca, and ended with the Ottoman surrender of Damascus. Fakhri Pasha, the Ottoman commander of Medina, resisted for more than two and half years during the Siege of Medina.

Along the border of Italian Libya and British Egypt, the Senussi tribe, incited and armed by the Turks, waged a small-scale guerrilla war against Allied troops. The British were forced to dispatch 12,000 troops to oppose them in the Senussi Campaign. Their rebellion was finally crushed in mid-1916.

Italian participation

Italy had been allied with the German and Austro-Hungarian Empires since 1882 as part of the Triple Alliance. However, the nation had its own designs on Austrian territory in Trentino, Istria and Dalmatia. Rome had a secret 1902 pact with France, effectively nullifying its alliance. At the start of hostilities, Italy refused to commit troops, arguing that the Triple Alliance was defensive in nature, and that Austria–Hungary was an aggressor. The Austro-Hungarian government began negotiations to secure Italian neutrality, offering the French colony of Tunisia in return. The Allies made a counter-offer in which Italy would receive the Southern Tyrol, Julian March and territory on the Dalmatian coast after the defeat of Austria-Hungary. This was formalised by the Treaty of London. Further encouraged by the Allied invasion of Turkey in April 1915, Italy joined the Triple Entente and declared war on Austria-Hungary on 23 May. Fifteen months later Italy declared war on Germany.

Militarily, the Italians had numerical superiority. This advantage, however, was lost, not only because of the difficult terrain in which fighting took place, but also because of the strategies and tactics employed. Field Marshal Luigi Cadorna, a staunch proponent of the frontal assault, had dreams of breaking into the Slovenian plateau, taking Ljubljana and threatening Vienna. It was a Napoleonic plan, which had no realistic chance of success in an age of barbed wire, machine guns, and indirect artillery fire, combined with hilly and mountainous terrain.

On the Trentino front, the Austro-Hungarians took advantage of the mountainous terrain, which favoured the defender. After an initial strategic retreat, the front remained largely unchanged, while Austrian Kaiserschützen and Standschützen engaged Italian Alpini in bitter hand-to-hand combat throughout the summer. The Austro-Hungarians counter attacked in the Altopiano of Asiago, towards Verona and Padua, in the spring of 1916, (Strafexpedition), but made little progress.

Beginning in 1915, the Italians under Cadorna mounted eleven offensives on the Isonzo front along the Isonzo River, north east of Trieste. All eleven offensives were repelled by the Austro-Hungarians, who held the higher ground. In the summer of 1916, the Italians captured the town of Gorizia. After this minor victory, the front remained static for over a year, despite several Italian offensives. In the autumn of 1917, thanks to the improving situation on the Eastern front, the Austro-Hungarian troops received large numbers of reinforcements, including German Stormtroopers and the elite Alpenkorps. The Central Powers launched a crushing offensive on 26 October 1917, spearheaded by the Germans. They achieved a victory at Caporetto. The Italian army was routed and retreated more than 100 kilometres (60 mi.) to reorganise, stabilising the front at the Piave River. Since in the Battle of Caporetto the Italian Army had heavy losses, the Italian Government called to arms the so-called '99 Boys (Ragazzi del '99), that is, all males who were 18 years old. In 1918, the Austro-Hungarians failed to break through, in a series of battles on the Piave River and, finally being decisively defeated in the Battle of Vittorio Veneto in October of that year. Austria-Hungary surrendered in early November 1918.

Romanian participation

inspecting Romanian troops]] Romania had been allied with the Central Powers since 1882. When the war began, however, it declared its neutrality, arguing that because Austria-Hungary had itself declared war on Serbia, Romania was under no obligation to join the war. When the Entente Powers promised Romania large territories of eastern Hungary (Transylvania and Banat), that had a large Romanian population, in exchange for Romania’s declaring war on the Central Powers, the Romanian government renounced its neutrality, and on 27 August 1916 the Romanian Army launched an attack against Austria-Hungary, with limited Russian support. The Romanian offensive was initially successful, pushing back the Austro-Hungarian troops in Transylvania, but a counter attack by the forces of the Central Powers drove back the Russo-Romanian forces and as a result of the Battle of Bucharest the Central Powers occupied Bucharest on 6 December 1916. Fighting in Moldova continued in 1917, resulting in a costly stalemate for the Central Powers. As Russia withdrew from the war in late 1917 as a result of the October Revolution, Romania was forced to sign an armistice with the Central Powers on 9 December 1917.

In January 1918, Romanian forces established control over Bessarabia as the Russian Army abandoned the province. Although a treaty was signed by the Romanian and the Bolshevik Russian government following talks between 5–9 March 1918 on the withdrawal of Romanian forces from Bessarabia within two months, on 27 March 1918 Romania attached Bessarabia to its territory, formally based on a resolution passed by the local assembly of the territory on the unification with Romania.

Romania officially made peace with the Central Powers by signing the Treaty of Bucharest on 7 May 1918. Under that treaty Romania was obliged to cease war with the Central Powers and make small territorial concessions for Austria-Hungary, ceding control of some passes in the Carpathian Mountains and grant oil concessions for Germany. In exchange, the Central Powers recognised the sovereignty of Romania over Bessarabia. The treaty was renounced in October 1918 by the Alexandru Marghiloman government and Romania nominally re-entered the war on 10 November 1918. The next day, the Treaty of Bucharest was nullified by the terms of the Armistice of Compiègne. Total Romanian deaths from 1914 to 1918, military and civilian, within contemporary borders, were estimated at 748,000.

The role of India

The war began with an unprecedented outpouring of loyalty and goodwill towards the United Kingdom from within the mainstream political leadership, contrary to initial British fears of an Indian revolt. The Indian Army in fact outnumbered the British Army at the beginning of the war. India under British rule contributed greatly to the British war effort by providing men and resources. This was done by the Indian Congress in hope of achieving self-government as India was very much under the control of the British. The United Kingdom disappointed the Indians by not providing self-governance, leading to the Gandhian Era in Indian history. About 1.3 million Indian soldiers and labourers served in Europe, Africa, and the Middle East, while both the Indian government and the princes sent large supplies of food, money, and ammunition. In all 140,000 men served on the Western Front and nearly 700,000 in the Middle East. Casualties of Indian soldiers totalled 47,746 killed and 65,126 wounded during World War I.

Eastern Front

Initial actions

While the Western Front had reached stalemate, the war continued in East Europe. Initial Russian plans called for simultaneous invasions of Austrian Galicia and German East Prussia. Although Russia's initial advance into Galicia was largely successful, they were driven back from East Prussia by Hindenburg and Ludendorff at Tannenberg and the Masurian Lakes in August and September 1914. Russia's less developed industrial base and ineffective military leadership was instrumental in the events that unfolded. By the spring of 1915, the Russians had retreated into Galicia, and in May the Central Powers achieved a remarkable breakthrough on Poland's southern frontiers. On 5 August they captured Warsaw and forced the Russians to withdraw from Poland.

Russian Revolution

Despite the success of the June 1916 Brusilov Offensive in eastern Galicia, dissatisfaction with the Russian government's conduct of the war grew. The success was undermined by the reluctance of other generals to commit their forces to support the victory. Allied and Russian forces were revived only temporarily with Romania's entry into the war on 27 August. German forces came to the aid of embattled Austro-Hungarian units in Transylvania and Bucharest fell to the Central Powers on 6 December. Meanwhile, unrest grew in Russia, as the Tsar remained at the front. Empress Alexandra's increasingly incompetent rule drew protests and resulted in the murder of her favourite, Rasputin, at the end of 1916.

In March 1917, demonstrations in Petrograd culminated in the abdication of Tsar Nicholas II and the appointment of a weak Provisional Government which shared power with the Petrograd Soviet socialists. This arrangement led to confusion and chaos both at the front and at home. The army became increasingly ineffective. The manpower required for German occupation of former Russian territory may have contributed to the failure of the Spring Offensive, however, and secured relatively little food or other materiel.

With the adoption of the Treaty of Brest-Litovsk, the Entente no longer existed. The Allied powers led a small-scale invasion of Russia, partly to stop Germany from exploiting Russian resources and, to a lesser extent, to support the "Whites" (as opposed to "Reds") in the Russian Civil War. Allied troops landed in Archangel and in Vladivostok.

Central Powers proposal for starting peace negotiations

In December 1916, after ten brutal months of the Battle of Verdun and a successful offensive against Romania, the Germans attempted to negotiate a peace with the Allies. Soon after, U.S. President Wilson attempted to intervene as a peacemaker, asking in a note for both sides to state their demands. Lloyd George's War Cabinet considered the German offer as a ploy to create divisions amongst the Allies. After initial outrage and much deliberation, they took Wilson's note as a separate effort, signalling that the U.S. was on the verge of entering the war against Germany following the "submarine outrages". While the Allies debated a response to Wilson's offer, the Germans chose to rebuff it in favour of "a direct exchange of views". Learning of the German response, the Allied governments were free to make clear demands in their response of 14 January. They sought restoration of damages, the evacuation of occupied territories, reparations for France, Russia and Romania, and a recognition of the principle of nationalities. This included the liberation of Italians, Slavs, Romanians, Czecho-Slovaks, and the creation of a "free and united Poland". On the question of security, the Allies sought guarantees that would prevent or limit future wars, complete with sanctions, as a condition of any peace settlement. The negotiations failed and the Entente powers rejected the German offer, because Germany did not state any specific proposals. To Wilson the Entente powers stated, that they will not start peace negotiations until the Central powers evacuated all occupied Allied territories and provided indemnities for all damage which was done.

1917–1918

, with their machine guns amongst the ruins of a cathedral near the Marne, driving back the Germans. 1918]]

Developments in 1917

Events of 1917 proved decisive in ending the war, although their effects were not fully felt until 1918.

The British naval blockade began to have a serious impact on Germany. In response, in February 1917, the German General Staff convinced Chancellor Theobald von Bethmann-Hollweg to declare unrestricted submarine warfare, with the goal of starving Britain out of the war. German planners estimated that unrestricted submarine warfare would cost Britain a monthly shipping loss of 600,000 tons. While it was realised that the policy was also likely to bring the United States into the conflict, British shipping losses would be so high that it would be forced to sue for peace after 5 to 6 months, before American intervention could make an impact. In reality, tonnage sunk rose above 500,000 tons per month from February to July. It peaked at 860,000 tons in April. After July, the newly re-introduced convoy system became extremely effective in reducing the U-boat threat. Britain was safe from starvation while German industrial output fell, and the United States troops joined the war in large numbers far earlier than Germany had anticipated.

On 3 May 1917, during the Nivelle Offensive, the weary French 2nd Colonial Division, veterans of the Battle of Verdun, refused their orders, arriving drunk and without their weapons. Their officers lacked the means to punish an entire division, and harsh measures were not immediately implemented. Then, mutinies afflicted an additional 54 French divisions and saw 20,000 men desert. The other Allied forces attacked but sustained tremendous casualties. However, appeals to patriotism and duty, as well as mass arrests and trials, encouraged the soldiers to return to defend their trenches, although the French soldiers refused to participate in further offensive action. Robert Nivelle was removed from command by 15 May, replaced by General Philippe Pétain, who suspended bloody large-scale attacks.

, France, 1917]]

The victory of Austria–Hungary and Germany at the Battle of Caporetto led the Allies at the Rapallo Conference to form the Supreme War Council to coordinate planning. Previously, British and French armies had operated under separate commands.

In December, the Central Powers signed an armistice with Russia. This released large numbers of German troops for use in the west. With German reinforcements and new American troops pouring in, the outcome was to be decided on the Western front. The Central Powers knew that they could not win a protracted war, but they held high hopes for success based on a final quick offensive. Furthermore, the leaders of the Central Powers and the Allies became increasingly fearful of social unrest and revolution in Europe. Thus, both sides urgently sought a decisive victory.

Entry of the United States

Non-Intervention

The United States originally pursued a policy of non-intervention, avoiding conflict while trying to broker a peace. When a German U-boat sank the British liner Lusitania in 1915, with 128 Americans aboard, U.S. President Woodrow Wilson vowed, "America is too proud to fight" and demanded an end to attacks on passenger ships. Germany complied. Wilson unsuccessfully tried to mediate a settlement. He repeatedly warned the U.S. would not tolerate unrestricted submarine warfare, in violation of international law and U.S. ideas of human rights. Wilson was under pressure from former president Theodore Roosevelt, who denounced German acts as "piracy". Wilson's desire to have a seat at negotiations at war's end to advance the League of Nations also played a role. Wilson's Secretary of State, William Jennings Bryan, whose opinions had been ignored, resigned as he could no longer support the president's policy. Public opinion was angered at suspected German sabotage of Black Tom in Jersey City, New Jersey, and the Kingsland Explosion.

In January 1917, Germany resumed unrestricted submarine warfare. The German Foreign minister, in the Zimmermann Telegram, told Mexico that U.S. entry was likely once unrestricted submarine warfare began, and invited Mexico to join the war as Germany's ally against the United States. In return, the Germans would send Mexico money and help it recover the territories of Texas, New Mexico, and Arizona that Mexico lost during the Mexican-American War 70 years earlier. Wilson released the Zimmerman note to the public and Americans saw it as a casus belli—a cause for war.

U.S. declaration of war on Germany

After the sinking of seven U.S. merchant ships by submarines and the publication of the Zimmerman telegram, Wilson called for war on Germany, which the U.S. Congress declared on 6 April 1917.

First active U.S. participation

The United States was never formally a member of the Allies but became a self-styled "Associated Power". The United States had a small army, but, after the passage of the Selective Service Act, it drafted 2.8 million men and by summer 1918 was sending 10,000 fresh soldiers to France every day. In 1917, the U.S. Congress gave U.S. citizenship to Puerto Ricans when they were drafted to participate in World War I, as part of the Jones Act. Germany had miscalculated, believing it would be many more months before they would arrive and that the arrival could be stopped by U-boats.

The United States Navy sent a battleship group to Scapa Flow to join with the British Grand Fleet, destroyers to Queenstown, Ireland and submarines to help guard convoys. Several regiments of U.S. Marines were also dispatched to France. The British and French wanted U.S. units used to reinforce their troops already on the battle lines and not waste scarce shipping on bringing over supplies. The U.S. rejected the first proposition and accepted the second. General John J. Pershing, American Expeditionary Forces (AEF) commander, refused to break up U.S. units to be used as reinforcements for British Empire and French units. As an exception, he did allow African-American combat regiments to be used in French divisions. The Harlem Hellfighters fought as part of the French 16th Division, earning a unit Croix de guerre for their actions at Chateau-Thierry, Belleau Wood and Sechault. AEF doctrine called for the use of frontal assaults, which had long since been discarded by British Empire and French commanders because of the large loss of life.

Austrian offer of separate peace

In 1917, Emperor Charles I of Austria secretly attempted separate peace negotiations with Clemenceau, with his wife's brother Sixtus in Belgium as an intermediary, without the knowledge of Germany. When the negotiations failed, his attempt was revealed to Germany, resulting in a diplomatic catastrophe.

German Spring Offensive of 1918

German General Erich Ludendorff drew up plans (codenamed Operation Michael) for the 1918 offensive on the Western Front. The Spring Offensive sought to divide the British and French forces with a series of feints and advances. The German leadership hoped to strike a decisive blow before significant U.S. forces arrived. The operation commenced on 21 March 1918 with an attack on British forces near Amiens. German forces achieved an unprecedented advance of 60 kilometres (40 miles).

British and French trenches were penetrated using novel infiltration tactics, also named Hutier tactics, after General Oskar von Hutier. Previously, attacks had been characterised by long artillery bombardments and massed assaults. However, in the Spring Offensive of 1918, Ludendorff used artillery only briefly and infiltrated small groups of infantry at weak points. They attacked command and logistics areas and bypassed points of serious resistance. More heavily armed infantry then destroyed these isolated positions. German success relied greatly on the element of surprise.

The front moved to within 120 kilometres (75 mi) of Paris. Three heavy Krupp railway guns fired 183 shells on the capital, causing many Parisians to flee. The initial offensive was so successful that Kaiser Wilhelm II declared 24 March a national holiday. Many Germans thought victory was near. After heavy fighting, however, the offensive was halted. Lacking tanks or motorised artillery, the Germans were unable to consolidate their gains. This situation was not helped by the supply lines now being stretched as a result of their advance. The sudden stop was also a result of the four Australian Imperial Force (AIF) divisions that were "rushed" down, thus doing what no other army had done and stopping the German advance in its tracks. During that time the first Australian division was hurriedly sent north again to stop the second German breakthrough. troops blinded by tear gas during the Battle of Estaires, 10 April 1918.]]

General Foch pressed to use the arriving American troops as individual replacements. Pershing sought instead to field American units as an independent force. These units were assigned to the depleted French and British Empire commands on 28 March. A Supreme War Council of Allied forces was created at the Doullens Conference on 5 November 1917.

Following Operation Michael, Germany launched Operation Georgette against the northern English Channel ports. The Allies halted the drive with limited territorial gains for Germany. The German Army to the south then conducted Operations Blücher and Yorck, broadly towards Paris. Operation Marne was launched on 15 July, attempting to encircle Reims and beginning the Second Battle of the Marne. The resulting counterattack, starting the Hundred Days Offensive, marked their first successful Allied offensive of the war.

By 20 July the Germans were back across the Marne at their Kaiserschlacht starting lines, having achieved nothing. Following this last phase of the war in the West, the German Army never again regained the initiative. German casualties between March and April 1918 were 270,000, including many highly trained stormtroopers.

Meanwhile, Germany was falling apart at home. Anti-war marches became frequent and morale in the army fell. Industrial output was 53 percent of 1913 levels.

New states under war zone

In 1918, the internationally recognized Azerbaijan Democratic Republic, Democratic Republic of Armenia and Democratic Republic of Georgia bordering the Ottoman Empire and Russian Empire were established, as well as the unrecognized Centrocaspian Dictatorship and South West Caucasian Republic. Later, these unrecognized states were eliminated by Azerbaijan and Turkey.

In 1918, the Dashnaks of the Armenian national liberation movement declared the Democratic Republic of Armenia (DRA) through the Armenian Congress of Eastern Armenians (unified form of Armenian National Councils) after the dissolution of the Transcaucasian Democratic Federative Republic. Tovmas Nazarbekian became the first Commander-in-chief of the DRA. Enver Pasha ordered the creation of a new army to be named the Army of Islam. He ordered the Army of Islam into the DRA, with the goal of taking Baku on the Caspian Sea. This new offensive was strongly opposed by the Germans. In early May 1918, the Ottoman army attacked the newly declared DRA. Although the Armenians managed to inflict one defeat on the Ottomans at the Battle of Sardarabad, the Ottoman army won a later battle and scattered the Armenian army. The Republic of Armenia signed the Treaty of Batum in June 1918.

Allied victory: summer and autumn 1918

The Allied counteroffensive, known as the Hundred Days Offensive, began on 8 August 1918. The Battle of Amiens developed with III Corps British Fourth Army on the left, the French First Army on the right, and the Australian and Canadian Corps spearheading the offensive in the centre through Harbonnières. It involved 414 tanks of the Mark IV and Mark V type, and 120,000 men. They advanced 12 kilometres (7 miles) into German-held territory in just seven hours. Erich Ludendorff referred to this day as the "Black Day of the German army".

The Australian-Canadian spearhead at Amiens, a battle that was the beginning of Germany’s downfall, helped pull the British armies to the north and the French armies to the south forward. While German resistance on the British Fourth Army front at Amiens stiffened, after an advance as far as and concluded the battle there, the French Third Army lengthened the Amiens front on 10 August, when it was thrown in on the right of the French First Army, and advanced liberating Lassigny in fighting which lasted until 16 August. South of the French Third Army, General Charles Mangin (The Butcher) drove his French Tenth Army forward at Soissons on 20 August to capture eight thousand prisoners, two hundred guns and the Aisne heights overlooking and menacing the German position north of the Vesle. Another "Black day" as described by Erich Ludendorff.

Meanwhile General Byng of the Third British Army, reporting that the enemy on his front was thinning in a limited withdrawal, was ordered to attack with 200 tanks towards Bapaume, opening the Battle of Albert, with the specific orders of "To break the enemy's front, in order to outflank the enemies present battle front" (opposite the British Fourth Army at Amiens). Rawlinson’s Fourth British Army was able to battle its left flank forward between Albert and the Somme straightening the line between the advanced positions of the Third Army and the Amiens front which resulted in recapturing Albert at the same time. During the last week of August the pressure along a front against the enemy was heavy and unrelenting. From German accounts, "Each day was spent in bloody fighting against an ever and again on-storming enemy, and nights passed without sleep in retirements to new lines." According to Ludendorff “We had to admit the necessity ... to withdraw the entire front from the Scarpe to the Vesle.”

In nearly four weeks of fighting since 8 August, over 100,000 German prisoners were taken, 75,000 by the BEF and the rest by the French. Since "The Black Day of the German Army" the German High Command realised the war was lost and made attempts for a satisfactory end. The day after the battle Ludenforff told Colonel Mertz "We cannot win the war any more, but we must not lose it either." On 11 August he offered his resignation to the Kaiser, who refused it and replied, "I see that we must strike a balance. We have nearly reached the limit of our powers of resistance. The war must be ended." On 13 August at Spa, Hindenburg, Ludendorff, Chancellor and Foreign Minister Hintz agreed that the war could not be ended militarily and on the following day the German Crown Council decided victory in the field was now most improbable. Austria and Hungary warned that they could only continue the war until December and Ludendorff recommended immediate peace negotiations, to which the Kaiser responded by instructing Hintz to seek the mediation of the Queen of the Netherlands. Prince Rupprecht warned Prince Max of Baden "Our military situation has deteriorated so rapidly that I no longer believe we can hold out over the winter; it is even possible that a catastrophe will come earlier." On 10 September Hindenburg urged peace moves to Emperor Charles of Austria and Germany appealed to the Netherlands for mediation. On the 14 September Austria sent a note to all belligerents and neutrals suggesting a meeting for peace talks on neutral soil and on 15 September Germany made a peace offer to Belgium. Both peace offers were rejected and on 24 September OHL informed the leaders in Berlin that armistice talks were inevitable. The following week cooperating French and American units broke through in Champagne at the Battle of Blanc Mont Ridge, forcing the Germans off the commanding heights, and closing towards the Belgian frontier. The last Belgian town to be liberated before the armistice was Ghent, which the Germans held as a pivot until Allied artillery was brought up. The German army had to shorten its front and use the Dutch frontier as an anchor to fight rear-guard actions.

When Bulgaria signed a separate armistice on 29 September, the Allies gained control of Serbia and Greece. Ludendorff, having been under great stress for months, suffered something similar to a breakdown. It was evident that Germany could no longer mount a successful defence.

Meanwhile, news of Germany's impending military defeat spread throughout the German armed forces. The threat of mutiny was rife. Admiral Reinhard Scheer and Ludendorff decided to launch a last attempt to restore the "valour" of the German Navy. Knowing the government of Prince Maximilian of Baden would veto any such action, Ludendorff decided not to inform him. Nonetheless, word of the impending assault reached sailors at Kiel. Many rebelled and were arrested, refusing to be part of a naval offensive which they believed to be suicidal. Ludendorff took the blame—the Kaiser dismissed him on 26 October. The collapse of the Balkans meant that Germany was about to lose its main supplies of oil and food. The reserves had been used up, but U.S. troops kept arriving at the rate of 10,000 per day.

Having suffered over 6 million casualties, Germany moved towards peace. Prince Maximilian of Baden took charge of a new government as Chancellor of Germany to negotiate with the Allies. Telegraphic negotiations with President Wilson began immediately, in the vain hope that better terms would be offered than by the British and French. Instead Wilson demanded the abdication of the Kaiser. There was no resistance when the social democrat Philipp Scheidemann on 9 November declared Germany to be a republic. Imperial Germany was dead; a new Germany had been born: the Weimar Republic.

Armistices and capitulations

after agreeing to the armistice that ended the war, Foch is seen second from the right. The carriage seen in the background, where the armistice was signed, later was chosen as the symbolic setting of Pétain's June 1940 armistice. It was moved to Berlin as a prize, but because of Allied bombing it was eventually moved to Crawinkel, Thuringia, where it was deliberately destroyed by SS troops in 1945.]] The collapse of the Central Powers came swiftly. Bulgaria was the first to sign an armistice on 29 September 1918 at Saloniki. On 30 October, the Ottoman Empire capitulated at Moudros (Armistice of Mudros).

Allied superiority and the stab-in-the-back legend, November 1918

In November 1918 the Allies had ample supplies of men and materiel to invade Germany, yet at the time of the armistice, no Allied force had crossed the German frontier and Berlin was still almost from the Western Front. The Kaiser's armies had also retreated from the battlefield in good order which enabled Hindenburg and other senior German leaders to spread the story that their armies had not really been defeated. This resulted in the stab-in-the-back legend which attributed Germany's losing the war not to its inability to continue fighting (even though up to a million soldiers were suffering from the 1918 flu pandemic and unfit to fight), but to the public's failure to respond to its "patriotic calling" and the intentional sabotaging of the war effort, particularly by Jews, Socialists and Bolsheviks.

A formal state of war between the two sides persisted for another seven months, until signing of the Treaty of Versailles with Germany on 28 June 1919. Later treaties with Austria, Hungary, Bulgaria and the Ottoman Empire were signed. However, the latter treaty with the Ottoman Empire was followed by strife (the Turkish War of Independence) and a final peace treaty was signed between the Allied Powers and the country that would shortly become the Republic of Turkey, at Lausanne on 24 July 1923.

Some war memorials date the end of the war as being when the Versailles treaty was signed in 1919; by contrast, most commemorations of the war's end concentrate on the armistice of 11 November 1918. Legally the last formal peace treaties were not signed until the Treaty of Lausanne. Under its terms, the Allied forces divested Constantinople on 23 August 1923.

Technology

The First World War began as a clash of 20-century technology and 19th-century tactics, with inevitably large casualties. By the end of 1917, however, the major armies, now numbering millions of men, had modernised and were making use of telephone, wireless communication, armoured cars, tanks, and aircraft. Infantry formations were reorganised, so that 100 man companies were no longer the main unit of manoeuvre. Instead, squads of 10 or so men, under the command of a junior NCO, were favoured. Artillery also underwent a revolution.

In 1914, cannons were positioned in the front line and fired directly at their targets. By 1917, indirect fire with guns (as well as mortars and even machine guns) was commonplace, using new techniques for spotting and ranging, notably aircraft and the often overlooked field telephone. Counter-battery missions became commonplace, also, and sound detection was used to locate enemy batteries.

Germany was far ahead of the Allies in utilising heavy indirect fire. She employed 150 and 210 mm howitzers in 1914 when the typical French and British guns were only 75 and 105 mm. The British had a 6 inch (152 mm) howitzer, but it was so heavy it had to be hauled to the field in pieces and assembled. Germans also fielded Austrian 305 mm and 420 mm guns, and already by the beginning of the war had inventories of various calibers of Minenwerfer ideally suited for trench warfare.

Much of the combat involved trench warfare, where hundreds often died for each yard gained. Many of the deadliest battles in history occurred during the First World War. Such battles include Ypres, the Marne, Cambrai, the Somme, Verdun, and Gallipoli. The Haber process of nitrogen fixation was employed to provide the German forces with a constant supply of gunpowder, in the face of British naval blockade. Artillery was responsible for the largest number of casualties and consumed vast quantities of explosives. The large number of head-wounds caused by exploding shells and fragmentation forced the combatant nations to develop the modern steel helmet, led by the French, who introduced the Adrian helmet in 1915. It was quickly followed by the Brodie helmet, worn by British Imperial and U.S. troops, and in 1916 by the distinctive German Stahlhelm, a design, with improvements, still in use today. {|class="toccolours" style="float: right; margin-left: 1em; margin-right: 2em; font-size: 85%; background:#white; color:black; width:30em; max-width: 40%;" cellspacing="5" |style="text-align: left;"|"Gas! Gas! Quick, boys!... Fitting the clumsy helmets just in time; But someone still was yelling out and stumbling, And flound'ring like a man in fire or lime... Dim, through the misty panes and thick green light, As under a green sea, I saw him drowning."- Wilfred Owen, DULCE ET DECORUM EST, 1917 |} The widespread use of chemical warfare was a distinguishing feature of the conflict. Gases used included chlorine, mustard gas and phosgene. Few war casualties were caused by gas, as effective countermeasures to gas attacks were quickly created, such as gas masks. The use of chemical warfare and small-scale strategic bombing were both outlawed by the 1907 Hague Conventions, and both proved to be of limited effectiveness, though they captured the public imagination.

The most powerful land-based weapons were railway guns weighing hundreds of tons apiece. These were nicknamed Big Berthas, even though the namesake was not a railway gun. Germany developed the Paris Gun, able to bombard Paris from over 100 kilometres (60 mi), though shells were relatively light at 94 kilograms (210 lb). While the Allies had railway guns, German models severely out-ranged and out-classed them.

Sopwith Camel. In April 1917, the average life expectancy of a British pilot on the Western Front was 93 flying hours.]]

Fixed-wing aircraft were first used militarily by the Italians in Libya 23 October 1911 during the Italo-Turkish War for reconnaissance, soon followed by the dropping of grenades and aerial photography the next year. By 1914 the military utility was obvious. They were initially used for reconnaissance and ground attack. To shoot down enemy planes, anti-aircraft guns and fighter aircraft were developed. Strategic bombers were created, principally by the Germans and British, though the former used Zeppelins as well. Towards the end of the conflict, aircraft carriers were used for the first time, with HMS Furious launching Sopwith Camels in a raid to destroy the Zeppelin hangars at Tondern in 1918. s for attacking observation balloons.]] German U-boats (submarines) were deployed after the war began. Alternating between restricted and unrestricted submarine warfare in the Atlantic, they were employed by the Kaiserliche Marine in a strategy to deprive the British Isles of vital supplies. The deaths of British merchant sailors and the seeming invulnerability of U-boats led to the development of depth charges (1916), hydrophones (passive sonar, 1917), blimps, hunter-killer submarines (HMS R&-1, 1917), forward-throwing anti-submarine weapons, and dipping hydrophones (the latter two both abandoned in 1918). To extend their operations, the Germans proposed supply submarines (1916). Most of these would be forgotten in the interwar period until World War II revived the need.

Trenches, machine guns, air reconnaissance, barbed wire, and modern artillery with fragmentation shells helped bring the battle lines of World War I to a stalemate. The British sought a solution with the creation of the tank and mechanised warfare. The first tanks were used during the Battle of the Somme on 15 September 1916. Mechanical reliability became an issue, but the experiment proved its worth. Within a year, the British were fielding tanks by the hundreds and showed their potential during the Battle of Cambrai in November 1917, by breaking the Hindenburg Line, while combined arms teams captured 8000 enemy soldiers and 100 guns. Light automatic weapons and submachine guns were also introduced during the conflict, such as the Lewis Gun, the Browning automatic rifle, and the Bergmann MP18.

Manned observation balloons, floating high above the trenches, were used as stationary reconnaissance platforms, reporting enemy movements and directing artillery. Balloons commonly had a crew of two, equipped with parachutes. If there was an enemy air attack, the crew could parachute to safety. At the time, parachutes were too heavy to be used by pilots of aircraft (with their marginal power output) and smaller versions would not be developed until the end of the war; they were also opposed by British leadership, who feared they might promote cowardice. Recognised for their value as observation platforms, balloons were important targets of enemy aircraft. . Approximately 10,000 German troops were killed when the 19 mines were simultaneously detonated.]] To defend against air attack, they were heavily protected by antiaircraft guns and patrolled by friendly aircraft; to attack them, unusual weapons such as air-to-air rockets were even tried. Blimps and balloons contributed to air-to-air combat among aircraft, because of their reconnaissance value, and to the trench stalemate, because it was impossible to move large numbers of troops undetected. The Germans conducted air raids on England during 1915 and 1916 with airships, hoping to damage British morale and cause aircraft to be diverted from the front lines. The resulting panic took several squadrons of fighters from France. The Ottomans saw the entire Armenian population as an enemy that had chosen to side with Russia at the beginning of the war. In early 1915, a number of Armenian nationalist groups, such as the Armenakan, Dashnak and Hunchak organisations, joined the Russian forces, and the Ottoman government used this as a pretext to issue the Tehcir Law. This authorised the deportation of the Armenians from eastern Anatolia to Syria between 1915 and 1917. The exact number of deaths is unknown, although Balakian gives a range of 250,000 to 1.5 million for the deaths of Armenians, the International Association of Genocide Scholars estimates over 1 million.

Russian Empire

Approximately 200,000 Germans living in Volhynia and about 600,000 Jews were deported by the Russian authorities. In 1916, an order was issued to deport around 650,000 Volga Germans to the east as well, but the Russian Revolution prevented this from being carried out. Many pogroms accompanied the Revolution of 1917 and the ensuing Russian Civil War, 60,000–200,000 civilian Jews were killed in the atrocities throughout the former Russian Empire.

Rape of Belgium

In Belgium, German troops, in fear of French and Belgian guerrilla fighters, or francs-tireurs, massacred townspeople in Andenne (211 dead), Tamines (384 dead), and Dinant (612 dead). On 25 August 1914, the Germans set fire to the town of Leuven, burned the library containing about 230,000 books, killed 209 civilians and forced 42,000 to evacuate. These actions brought worldwide condemnation.

Soldiers' experiences

to the 1 Lincolns, training in Bermuda for the Western Front, winter 1914–1915. One in four survived the war.]]

The soldiers of the war were initially volunteers, except for Italy, but increasingly were conscripted into service. Britain's Imperial War Museum has collected more than 2,500 recordings of soldiers' personal accounts and selected transcripts, edited by military author Max Arthur, have been published. The museum believes that historians have not taken full account of this material and accordingly has made the full archive of recordings available to authors and researchers. Surviving veterans, returning home, often found that they could only discuss their experiences amongst themselves. Grouping together, they formed "veterans' associations" or "Legions".

Prisoners of war

.]] About 8 million men surrendered and were held in POW camps during the war. All nations pledged to follow the Hague Convention on fair treatment of prisoners of war. A POW's rate of survival was generally much higher than their peers at the front. Individual surrenders were uncommon. Large units usually surrendered en masse. At the Battle of Tannenberg 92,000 Russians surrendered. When the besieged garrison of Kaunas surrendered in 1915, some 20,000 Russians became prisoners. Over half of Russian losses were prisoners (as a proportion of those captured, wounded or killed); for Austria-Hungary 32%, for Italy 26%, for France 12%, for Germany 9%; for Britain 7%. Prisoners from the Allied armies totalled about 1.4 million (not including Russia, which lost 2.-3.5 million men as prisoners.) From the Central Powers about 3.3 million men became prisoners.

Germany held 2.5 million prisoners; Russia held 2.9 million; while Britain and France held about 720,000. Most were captured just prior to the Armistice. The U.S. held 48,000. The most dangerous moment was the act of surrender, when helpless soldiers were sometimes gunned down. Once prisoners reached a camp, in general, conditions were satisfactory (and much better than in World War II), thanks in part to the efforts of the International Red Cross and inspections by neutral nations. Conditions were terrible in Russia, starvation was common for prisoners and civilians alike; about 15–20% of the prisoners in Russia died. In Germany food was scarce, but only 5% died.

The Ottoman Empire often treated POWs poorly. Some 11,800 British Empire soldiers, most of them Indians, became prisoners after the Siege of Kut, in Mesopotamia, in April 1916, 4,250 died in captivity. Although many were in very bad condition when captured, Ottoman officers forced them to march to Anatolia. A survivor said: "we were driven along like beasts, to drop out was to die." The survivors were then forced to build a railway through the Taurus Mountains.

In Russia, where the prisoners from the Czech Legion of the Austro-Hungarian army were released in 1917 they re-armed themselves and briefly became a military and diplomatic force during the Russian Civil War.

While the Allied prisoners of the Central Powers were quickly sent home at the end of active hostilities, the same treatment was not granted to Central Power prisoners of the Allies and Russia, many of which had to serve as forced labor, e.g. in France until 1920. They were only released after many approaches by the Red Cross to the Allied Supreme Council. There were still German prisoners being held in Russia as late as 1924.

Military attachés and war correspondents

Military and civilian observers from every major power closely followed the course of the war. Many were able to report on events from a perspective somewhat akin to modern "embedded" positions within the opposing land and naval forces. These military attachés and other observers prepared voluminous first-hand accounts of the war and analytical papers.

For example, former U.S. Army Captain Granville Fortescue followed the developments of the Gallipoli Campaign from an embedded perspective within the ranks of the Turkish defenders; and his report was passed through Turkish censors before being printed in London and New York. However, this observer's role was abandoned when the U.S. entered the war, as Fortescue immediately re-enlisted, sustaining wounds at Forest of Argonne in the Meuse-Argonne Offensive, September 1918.

In-depth observer narratives of the war and more narrowly focused professional journal articles were written soon after the war; and these post-war reports conclusively illustrated the battlefield destructiveness of this conflict. This was not the first time the tactics of entrenched positions for infantry defended with machine guns and artillery became vitally important. The Russo-Japanese War had been closely observed by Military attachés, war correspondents and other observers; but, from a 21st century perspective, it is now apparent that a range of tactical lessons were disregarded or not used in the preparations for war in Europe and throughout the Great War.

Support and opposition to the war

Support

The war was primarily supported by nationalists, industrial producers, and imperialists. In the Balkans, Yugoslav nationalists such as Yugoslav nationalist leader Ante Trumbić in the Balkans strongly supported the war, desiring the freedom of Yugoslavs from Austria-Hungary and other foreign powers and the creation of an independent Yugoslavia. The Yugoslav Committee was formed in Paris on 30 April 1915 but shortly moved its office to London, Trumbić led the Committee. In 1916, the Arab Revolt began in Ottoman-controlled territories of the Middle East in an effort to achieve independence. The Italian Liberal Party under the leadership of Paolo Boselli promoted intervention in the war on the side of the Allies and utilised the Dante Aligheri Society to promote Italian nationalism.

A number of socialist parties initially supported the war when it began in August 1914. Initially European socialists became split on national lines with the conception of class conflict held by radical socialists such as Marxists and syndicalists being overstepped by their support for war. Once the war began, Austrian, British, French, German and Russian socialists followed the rising nationalist current by supporting their country's intervention in the war.

Italian socialists were divided on whether to support the war or oppose it, some were militant supporters of the war including Benito Mussolini and Leonida Bissolati. However the Italian Socialist Party decided to oppose the war after anti-militarist protestors had been killed, resulting in a general strike called Red Week. The Italian Socialist Party purged itself of pro-war nationalist members, including Mussolini. Mussolini's nationalism enabled him to raise funds from Ansaldo (an armaments firm) and other companies to create Il Popolo d'Italia to convince socialists and revolutionaries to support the war.

In April 1918 the Rome Congress of Oppressed Nationalities was held that included Czechoslovak, Italian, Polish, Transylvanian, and Yugoslav representatives that urged the Allies to support national self-determination for the peoples residing within Austria-Hungary. Having voiced these sentiments did not hinder Smith-Dorien's career, or preventing him from doing his duty in World War I to the best of his abilities.

Many countries jailed those who spoke out against the conflict. These included Eugene Debs in the United States and Bertrand Russell in Britain. In the U.S., the Espionage Act of 1917 and Sedition Act of 1918 made it a federal crime to oppose military recruitment or make any statements deemed "disloyal". Publications at all critical of the government were removed from circulation by postal censors, The war had begun amid the Home Rule crisis in Ireland that had begun in 1912 and by 1914 there was a serious possibility of an outbreak of civil war in Ireland between Irish unionists and republicans.

Other opposition came from conscientious objectors – some socialist, some religious – who refused to fight. In Britain 16,000 people asked for conscientious objector status. Many suffered years of prison, including solitary confinement and bread and water diets. Even after the war, in Britain many job advertisements were marked "No conscientious objectors need apply".

The Central Asian Revolt started in the summer of 1916, when the Russian Empire government ended its exemption of Muslims from military service.

In 1917, a series of mutinies in the French army led to dozens of soldiers being executed and many more imprisoned.

In Milan in May 1917, Bolshevik revolutionaries organised and engaged in rioting calling for an end to the war, and managed to close down factories and stop public transportation. The Italian army was forced to enter Milan with tanks and machine guns to face Bolsheviks and anarchists who fought violently until May 23 when the army gained control of the city with almost fifty people killed (three of which were Italian soldiers) and over 800 people arrested. Out of approximately 625,000 Canadians who served, about 60,000 were killed and another 173,000 were wounded.

In 1917, Emperor Charles I of Austria secretly entered into peace negotiations with the Allied powers, with his brother-in-law Sixtus as intermediary, without the knowledge of his ally Germany. He failed, however, because of the resistance of Italy.

In September 1917, the Russian soldiers in France began questioning why they were fighting for the French at all and mutinied. In Russia, opposition to the war led to soldiers also establishing their own revolutionary committees and helped foment the October Revolution of 1917, with the call going up for "bread, land, and peace". The Bolsheviks reached a peace treaty with Germany, the peace of Brest-Litovsk, despite its harsh conditions.

The end of October 1918, in northern Germany, saw the beginning of the German Revolution of 1918–19. Units of the German Navy refused to set sail for a last, large-scale operation in a war which they saw as good as lost, initiating the uprising. The sailors' revolt which then ensued in the naval ports of Wilhelmshaven and Kiel spread across the whole country within days and led to the proclamation of a republic on 9 November 1918 and shortly thereafter to the abdication of Kaiser Wilhelm II.

Conscription

As the war slowly turned into a war of attrition, conscription was implemented in some countries. This issue was particularly explosive in Canada and Australia. In the former it opened a political gap between French-Canadians, who claimed their true loyalty was to Canada and not the British Empire, and the Anglophone majority who saw the war as a duty to both Britain and Canada. Prime Minister Robert Borden pushed through a Military Service Act, provoking the Conscription Crisis of 1917. In Australia, a sustained pro-conscription campaign by Prime Minister Billy Hughes, caused a split in the Australian Labor Party and Hughes formed the Nationalist Party of Australia in 1917 to pursue the matter. Nevertheless, the labour movement, the Catholic Church, and Irish nationalist expatriates successfully opposed Hughes' push, which was rejected in two plebiscites.

Conscription put into uniform nearly every physically fit man in Britain, six of ten million eligible. Of these, about 750,000 lost their lives and 1,700,000 were wounded. Most deaths were to young unmarried men; however, 160,000 wives lost husbands and 300,000 children lost fathers.

Aftermath

Health and economic effects

{|class="toccolours" style="float: right; margin-left: 1em; margin-right: 2em; font-size: 99%; background:#white; color:black; width:30em; max-width: 40%;" cellspacing="5" |style="text-align: left;"| ..."Strange, friend," I said, "Here is no cause to mourn." "None," said the other, "Save the undone years"... |- |style="text-align: left;" |— Wilfred Owen, Strange Meeting, 1918 not counting other casualties. Germany and Russia were similarly affected.

The war had profound economic consequences. Of the 60 million European soldiers who were mobilised from 1914–1918, 8 million were killed, 7 million were permanently disabled, and 15 million were seriously injured. Germany lost 15.1% of its active male population, Austria–Hungary lost 17.1%, and France lost 10.5%. About 750,000 German civilians died from starvation caused by the British blockade during the war. By the end of the war, famine had killed approximately 100,000 people in Lebanon. The best estimates of the death toll from the Russian famine of 1921 run from 5 million to 10 million people. By 1922, there were between 4.5 million and 7 million homeless children in Russia as a result of nearly a decade of devastation from World War I, the Russian Civil War, and the subsequent famine of 1920–1922. Numerous anti-Soviet Russians fled the country after the Revolution; by the 1930s the northern Chinese city of Harbin had 100,000 Russians. Thousands more emigrated to France, England and the United States. , 1922]] nurses tend to 1918 flu pandemic patients in temporary wards set up inside Oakland Municipal Auditorium, 1918.]] Diseases flourished in the chaotic wartime conditions. In 1914 alone, louse-borne epidemic typhus killed 200,000 in Serbia. From 1918 to 1922, Russia had about 25 million infections and 3 million deaths from epidemic typhus. Whereas before World War I, Russia had about 3.5 million cases of malaria, its people suffered more than 13 million cases in 1923. In addition, a major influenza epidemic spread around the world. Overall, the 1918 flu pandemic killed at least 50 million people.

Lobbying by Chaim Weizmann and fear that American Jews would encourage the USA to support Germany culminated in the British government's Balfour Declaration of 1917, endorsing creation of a Jewish homeland in Palestine. A total of more than 1,172,000 Jewish soldiers served in the Allied and Central Power forces in World War I, including 450,000 in Czarist Russia and 275,000 in Austria-Hungary.

The social disruption and widespread violence of the Revolution of 1917 and the ensuing Russian Civil War sparked more than 2,000 pogroms in the former Russian Empire, mostly in the Ukraine. An estimated 60,000–200,000 civilian Jews were killed in the atrocities.

In the aftermath of World War I, Greece fought against Turkish nationalists led by Mustafa Kemal, a war which resulted in a massive population exchange between the two countries under the Treaty of Lausanne. According to various sources, several hundred thousand Pontic Greeks died during this period.

Peace treaties and national boundaries

After the war, the Paris Peace Conference imposed a series of peace treaties on the Central Powers. The 1919 Treaty of Versailles officially ended the war. Building on Wilson's 14th point, the Treaty of Versailles also brought into being the League of Nations on 28 June 1919.

In signing the treaty, Germany acknowledged responsibility for the war, agreeing to pay enormous war reparations and award territory to the victors. The "Guilt Thesis" became a controversial explanation of later events among analysts in Britain and the United States. The Treaty of Versailles caused enormous bitterness in Germany, which nationalist movements, especially the Nazis, exploited with a conspiracy theory they called the Dolchstosslegende (Stab-in-the-back legend). The Weimar Republic lost the former colonial possessions and was saddled with accepting blame for the war, as well as paying punitive reparations for it. Unable to pay them with exports (a result of territorial losses and postwar recession), Germany did so by borrowing from the United States. Runaway inflation in the 1920s contributed to the economic collapse of the Weimar Republic and the reparations were suspended in 1931 following the Stock Market Crash in 1929 and the beginnings of the Great Depression worldwide.

Austria–Hungary was partitioned into several successor states, including Austria, Hungary, Czechoslovakia, and Yugoslavia, largely but not entirely along ethnic lines. Transylvania was shifted from Hungary to Greater Romania. The details were contained in the Treaty of Saint-Germain and the Treaty of Trianon. As a result of the Treaty of Trianon, 3.3 million Hungarians came under foreign rule. Although the Hungarians made up 54% of the population of the pre-war Kingdom of Hungary, only 32% of its territory was left to Hungary. Between 1920 and 1924, 354,000 Hungarians fled former Hungarian territories attached to Romania, Czechoslovakia and Yugoslavia.

The Russian Empire, which had withdrawn from the war in 1917 after the October Revolution, lost much of its western frontier as the newly independent nations of Estonia, Finland, Latvia, Lithuania, and Poland were carved from it. Bessarabia was re-attached to the Greater Romania, as it had been a Romanian territory for more than a thousand years.

The Ottoman Empire disintegrated, and much of its non-Anatolian territory was awarded as protectorates of various Allied powers. The Turkish core was reorganised as the Republic of Turkey. The Ottoman Empire was to be partitioned by the Treaty of Sèvres in 1920. This treaty was never ratified by the Sultan and was rejected by the Turkish republican movement, leading to the Turkish Independence War and, ultimately, to the 1923 Treaty of Lausanne.

Legacy

The first tentative efforts to comprehend the meaning and consequences of modern warfare began during the initial phases of the war, and this process continued throughout and after the end of hostilities.

Memorials

in the Somme.]] Memorials were erected in thousands of villages and towns. Close to battlefields, the improvised burial grounds were gradually moved to formal graveyards under the care of organisations such as the Commonwealth War Graves Commission, the American Battle Monuments Commission, the German War Graves Commission and Le Souvenir français. Many of these graveyards also have central monuments to the missing or unidentified dead, such as the Menin Gate memorial and the Thiepval Memorial to the Missing of the Somme.

of Canada, author of In Flanders Fields, died in 1918 of pneumonia.]] On 3 May 1915, during the Second Battle of Ypres, Lieutenant Alexis Helmer was killed. At his graveside, his friend John McCrae, M.D., of Guelph, Ontario, Canada wrote the memorable poem In Flanders Fields as a salute to those who perished in the Great War. Published in Punch on 8 December 1915, it is still recited today, especially on Remembrance Day and Memorial Day.

Liberty Memorial in Kansas City, Missouri is a United States memorial dedicated to all Americans who served in World War I. The site for the Liberty Memorial was dedicated on November 1, 1921. On this day, the supreme Allied commanders spoke to a crowd of more than 100,000 people. It was the only time in history these leaders were together in one place. In attendance were Lieutenant General Baron Jacques of Belgium; General Armando Diaz of Italy; Marshal Ferdinand Foch of France; General Pershing of the United States; and Admiral D. R. Beatty of Great Britain. After three years of construction, the Liberty Memorial was completed and President Calvin Coolidge delivered the dedication speech to a crowd of 150,000 people in 1926.

Liberty Memorial is also home to The National World War I Museum, the only museum dedicated soley to World War I in the United States.

Cultural memory

The First World War had a lasting impact on social memory. It was seen by many in Britain as signalling the end of Victorian England, and across Europe many regarded it as a watershed moment. Historian Samuel Hynes explained:

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This has become the most common perception of the First World War, perpetuated by the art, cinema, poems and stories published subsequently. Films such as All Quiet on the Western Front, Paths of Glory and For King and Country have perpetuated the idea; while war-time films including Camrades, Flanders Poppies and Shoulder Arms indicate that the most contemporary views of the war were overall far more positive. Likewise, the art of Paul Nash, John Nash, Christopher Nevison and Henry Tonks in Britain painted a negative view of the conflict in keeping with the growing perception, while popular war-time artists such as Muirhead Bone painted more serene and pleasant interpretations subsequently rejected as inaccurate. these perceptions of the war, they are nevertheless prevalent across much of society. They have dynamically changed according to contemporary influences, reflecting in the 1950s perceptions of the war as 'aimless' following the contrasting Second World War, and emphasising conflict within the ranks during times of class conflict in the 1960s. For years afterwards, people mourned the dead, the missing, and the many disabled. Many soldiers returned with severe trauma, suffering from shell shock (also called neurasthenia, now called posttraumatic stress disorder). Many more returned home with few after-effects; however, their silence about the war contributed to the conflict's growing mythological status. Such historians as Dan Todman, Paul Fussell and Samuel Heyns have all published works since the 1990s arguing that these common perceptions of the war are factually incorrect. World War II was in part a continuation of the power struggle never fully resolved by the First World War; in fact, it was common for Germans in the 1930s and 1940s to justify acts of international aggression because of perceived injustices imposed by the victors of the First World War.

The establishment of the modern state of Israel and the roots of the continuing Israeli-Palestinian Conflict are partially found in the unstable power dynamics of the Middle East which resulted from World War I. Prior to the end of the war, the Ottoman Empire had maintained a modest level of peace and stability throughout the Middle East. With the fall of Ottoman government, power vacuums developed and conflicting claims to land and nationhood began to emerge. The political boundaries drawn by the victors of the First World War were quickly imposed, sometimes after only cursory consultation with the local population. In many cases, these continue to be problematic in the 21st-century struggles for national identity. While the dissolution of the Ottoman Empire at the end of World War I was pivotal in contributing to the modern political situation of the Middle East, including the Arab-Israeli conflict, the end of Ottoman rule also spawned lesser known disputes over water and other natural resources.

Views in the United States

U.S. intervention in the war, as well as the Wilson administration, became deeply unpopular. This was reflected in the U.S. Senate's rejection of the Versailles treaty and membership in the League of Nations. In the interwar era a consensus arose that U.S. intervention was a mistake, and the Congress passed laws in an attempt to preserve U.S. neutrality in any future conflict. Polls taken in 1937 and the opening months of World War II established that nearly 60% regarded the intervention as a mistake, with only 28% opposing that view. But, in the period between the fall of France and the attack on Pearl Harbor, public opinion changed dramatically and, for the first time, a narrow plurality rejected the idea that the war was a mistake.

New national identities

Poland reemerged as an independent country, after more than a century. As a "minor Entente nation" and the country with the largest casualties per head the Kingdom of Serbia and its dynasty became the backbone of the new multinational state, the Kingdom of Serbs, Croats and Slovenes (later renamed Yugoslavia). Czechoslovakia became a new nation. Russia became the Soviet Union and lost Finland, Estonia, Lithuania and Latvia, which became independent countries. The Ottoman Empire was soon replaced by Turkey and several other countries in the Middle East.

In the British Empire, the war unleashed new forms of nationalism. In Australia and New Zealand the Battle of Gallipoli became known as those nations' "Baptism of Fire". It was the first major war in which the newly established countries fought and it was one of the first times that Australian troops fought as Australians, not just subjects of the British Crown. Anzac Day, commemorating the Australian and New Zealand Army Corps, celebrates this defining moment.

After the Battle of Vimy Ridge, where the Canadian divisions fought together for the first time as a single corps, Canadians began to refer to theirs as a nation "forged from fire". Having succeeded on the same battleground where the "mother countries" had previously faltered, they were for the first time respected internationally for their own accomplishments. Canada entered the war as a Dominion of the British Empire and remained so afterwards, although she emerged with a greater measure of independence. While the other Dominions were represented by Britain, Canada was an independent negotiator and signatory of the Versailles Treaty.

Economic effects

One of the most dramatic effects of the war was the expansion of governmental powers and responsibilities in Britain, France, the United States, and the Dominions of the British Empire. In order to harness all the power of their societies, new government ministries and powers were created. New taxes were levied and laws enacted, all designed to bolster the war effort; many of which have lasted to this day. Similarly, the war strained the abilities of the formerly large and bureaucratised governments such as in Austria–Hungary and Germany; however, any analysis of the long-term effects were clouded by the defeat of these governments. . When the war began in 1914, a dollar was worth 4.2 marks. By November 1923, the dollar was at 4.2 trillion marks.]] Gross domestic product (GDP) increased for three Allies (Britain, Italy, and U.S.), but decreased in France and Russia, in neutral Netherlands, and in the main three Central Powers. The shrinkage in GDP in Austria, Russia, France, and the Ottoman Empire reached 30 to 40%. In Austria, for example, most of the pigs were slaughtered and, at war's end, there was no meat.

All nations had increases in the government's share of GDP, surpassing fifty percent in both Germany and France and nearly reaching fifty percent in Britain. To pay for purchases in the United States, Britain cashed in its extensive investments in American railroads and then began borrowing heavily on Wall Street. President Wilson was on the verge of cutting off the loans in late 1916, but allowed a great increase in U.S. government lending to the Allies. After 1919, the U.S. demanded repayment of these loans, which, in part, were funded by German reparations, which, in turn, were supported by American loans to Germany. This circular system collapsed in 1931 and the loans were never repaid. In 1934, Britain owed the US $4.4 billion of World War I debt.

Macro- and micro-economic consequences devolved from the war. Families were altered by the departure of many men. With the death or absence of the primary wage earner, women were forced into the workforce in unprecedented numbers. At the same time, industry needed to replace the lost labourers sent to war. This aided the struggle for voting rights for women.

In Britain, rationing was finally imposed in early 1918, limited to meat, sugar, and fats (butter and oleo), but not bread. The new system worked smoothly. From 1914 to 1918 trade union membership doubled, from a little over four million to a little over eight million. Work stoppages and strikes became frequent in 1917–1918 as the unions expressed grievances regarding prices, alcohol control, pay disputes, fatigue from overtime and working on Sundays and inadequate housing.

Britain turned to her colonies for help in obtaining essential war materials whose supply had become difficult from traditional sources. Geologists such as Albert Ernest Kitson were called upon to find new resources of precious minerals in the African colonies. Kitson discovered important new deposits of manganese, used in munitions production, in the Gold Coast.

Article 231 of the Treaty of Versailles (the so-called "war guilt" clause) declared Germany and its allies responsible for all "loss and damage" suffered by the Allies during the war and provided the basis for reparations. The total reparations demanded was 132 billion gold marks which was far more than the total German gold or foreign exchange. The economic problems that the payments brought, and German resentment at their imposition, are usually cited as one of the more significant factors that led to the end of the Weimar Republic and the beginning of the dictatorship of Adolf Hitler. After Germany’s defeat in World War II, payment of the reparations was not resumed. There was, however, outstanding German debt that the Weimar Republic had used to pay the reparations. Germany finished paying off the reparations in October 2010.

See also

European Civil War

List of surviving veterans of World War I

List of last surviving World War I veterans by country

List of people associated with World War I

List of wars and anthropogenic disasters by death toll

Lists of wars

Lists of World War I topics

World War One – Medal Abbreviations

Effect of World War I on children in the United States

Despina Storch

Video

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Notes

References

For a comprehensive bibliography see List of books about World War I (translated from the German) , reviewed in . | publisher=University of California Press| issn=0030-8684}} , Wilson's maneuvering U.S. into war , general military history }} also published by Harper as "Ludendorff's Own Story, August 1914 – November 1918: The Great War from the Siege of Liege to the Signing of the Armistice as Viewed from the Grand Headquarters of the German Army" (original title Meine Kriegserinnerungen, 1914–1918) | journal=The Journal of Military History| volume=60| issue=3| month=July| year=1996| pages=495–511| doi=10.2307/2944522| publisher=Society for Military History| jstor=2944522}} cites "Cf. articles signed XXX in La Revue de Deux Mondes, March 1 and March 15, 1920" Deals with technical developments, including the first dipping hydrophones | doi=10.2307/1986064| publisher=Society for Military History| jstor=1986064 }} , major reinterpretation : the major scholarly synthesis. Thorough coverage of 1914 , reviewed at , tells of the opening diplomatic and military manoeuvres

External links

A multimedia history of World War I

British Pathé Online film archive containing extensive coverage of World War I

The Heritage of the Great War, Netherlands

The World War I Document Archive Wiki, Brigham Young University

Animated maps

An animated map "Europe plunges into war"

An animated map of Europe at the end of the war

A collection of vintage maps from all theaters of World War I

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