Intercontinental ballistic missile

An intercontinental ballistic missile (ICBM) is a guided ballistic missile with a minimum range of 5,500 kilometres (3,400 mi) primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Similarly conventional, chemical and biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs. Most modern designs support multiple independently targetable reentry vehicles (MIRVs), allowing a single missile to carry several warheads, each of which can strike a different target.

Early ICBMs had limited accuracy (circular error probable) that allowed them to be used only against the largest targets such as cities. They were seen as a "safe" basing option, one that would keep the deterrent force close to home where it would be difficult to attack. Attacks against (especially hardened) military targets, if desired, still demanded the use of a more precise manned bomber. This is due to the inverse-square law, which predicts that the amount of energy dispersed from a single point release of energy (such as a thermonuclear blast) dissipates by the inverse of the square of distance from the single point of release. The result is that the power of a nuclear explosion to rupture hardened structures is greatly decreased by the distance from the impact point of the nuclear weapon. So a near-direct hit is generally necessary, as only diminishing returns are gained by increasing bomb yield.

North Korea

Coordinates: 40°00′N 127°00′E / 40.000°N 127.000°E / 40.000; 127.000

North Korea ( listen), officially the Democratic People's Republic of Korea (DPRK; Chosŏn'gŭl: 조선민주주의인민공화국; hancha: 朝鮮民主主義人民共和國; MR: Chosŏn Minjujuŭi Inmin Konghwaguk), is a country in East Asia, in the northern part of the Korean Peninsula. The name Korea is derived from the Kingdom of Goguryeo, also spelled as Koryŏ. The capital and largest city is Pyongyang. North Korea shares a land border with China to the north and northwest, along the Amnok (Yalu) and Tumen rivers, and a small section of the Tumen River also forms a border with Russia to the northeast. The Korean Demilitarized Zone marks the boundary between North Korea and South Korea.

Korea was annexed by the Empire of Japan in 1910. After the Japanese surrender at the end of World War II in 1945, Korea was divided into two zones by the United States and the Soviet Union, with the north occupied by the Soviets and the south by the Americans. Negotiations on reunification failed, and in 1948 two separate governments were formed: the Democratic People's Republic of Korea in the north, and the Republic of Korea in the south. An invasion initiated by North Korea led to the Korean War (1950–53). Although the Korean Armistice Agreement brought about a ceasefire, no official peace treaty was ever signed. Both states were accepted into the United Nations in 1991.

LGM-30 Minuteman

The LGM-30 Minuteman is a US land-based intercontinental ballistic missile (ICBM), in service with the Air Force Global Strike Command. As of 2014, the LGM-30G Minuteman III version is the only land-based ICBM in service in the United States.

Development of the Minuteman began in the mid-1950s as the outgrowth of basic research into solid fuel rocket motors which indicated an ICBM based on solids was possible. Such a missile could stand ready for extended periods of time with little maintenance, and then launch on command. In comparison, existing US missile designs using liquid fuels required a lengthy fueling process immediately before launch, which left them open to the possibility of surprise attack. This potential for immediate launch gave the missile its name; like the Revolutionary War's Minutemen, the Minuteman was designed to be launched on a moment's notice.

Minuteman entered service in 1962 as a weapon tasked primarily with the deterrence role, threatening Soviet cities with a counterattack if the US was attacked. However, with the development of the US Navy's Polaris which addressed the same role, the Air Force began to modify Minuteman into a weapon with much greater accuracy with the specific intent of allowing it to attack hardened military targets, including Soviet missile silos. The Minuteman-II entered service in 1965 with a host of upgrades to improve its accuracy and survivability in the face of an anti-ballistic missile (ABM) system the Soviets were known to be developing. Minuteman-III followed in 1970, using three smaller warheads instead of one large one, which made it very difficult to attack by an anti-ballistic missile system which would have to hit all three widely separated warheads to be effective. Minuteman-III was the first multiple independently targetable reentry vehicle (MIRV) ICBM to be deployed. Each missile can carry up to three nuclear warheads, which have a yield in the range of 300 to 500 kilotons.

Air force

An air force, also known in some countries as an air army, is in the broadest sense, the national military organization that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an army, navy, or a marine corps. Typically, air forces are responsible for gaining control of the air, carrying out strategic and tactical bombing missions, and providing support to land and naval forces.

The term "air force" may also refer to a tactical air force or numbered air force, which is an operational formation either within a national air force or comprising several air components from allied nations. Air forces typically consist of a combination of fighters, bombers, helicopters, transport planes and other aircraft.

Many air forces are also responsible for operations of the military space, intercontinental ballistic missiles (ICBM), and communications equipment. Some air forces may command and control other air defence assets such as anti-aircraft artillery, surface-to-air missiles, or anti-ballistic missile warning networks and defensive systems. Some nations, principally Russia, the former Soviet Union and countries who modelled their militaries along Soviet lines, have an air defence force which is organizationally separate from their air force.

Ballistic missile

A ballistic missile is a missile (rocket) that follows a ballistic trajectory with the objective of delivering one or more warheads to a predetermined target. A ballistic missile is only guided during relatively brief periods of flight (there are unguided ballistic missiles as well, such as 9K52 Luna-M, although these may well be considered rockets), and most of its trajectory is unpowered and governed by gravity and air resistance if in the atmosphere. This contrasts to a cruise missile, which is aerodynamically guided in powered flight. Long range intercontinental ballistic missiles (ICBM) are launched at a steep, sub-orbital flight trajectory and spend most of their flight out of the atmosphere. Shorter range ballistic missiles stay within the Earth's atmosphere.

History

Rockets have been used as weapons for a long time (see History of rockets). A pioneer ballistic missile was the A-4, commonly known as the V-2 rocket developed by Nazi Germany in the 1930s and 1940s under the direction of Wernher von Braun. The first successful launch of a V-2 was on October 3, 1942, and it began operation on September 6, 1944 against Paris, followed by an attack on London two days later. By the end of World War II in May 1945, over 3,000 V-2s had been launched.