Casus belli

Casus belli is a Latin expression meaning "an act or event that provokes or is used to justify war" (literally, "a case for war"). A casus belli involves direct offenses or threats against the nation declaring the war, whereas a casus foederis involves offenses or threats against its ally—usually one bound by a mutual defense pact. Either may be considered an act of war.

The term came into wide use in the seventeenth and eighteenth centuries through the writings of Hugo Grotius (1653), Cornelius van Bynkershoek (1707), and Jean-Jacques Burlamaqui (1732), among others, and due to the rise of the political doctrine of jus ad bellum or "just war theory". The term is also used informally to refer to any "just cause" a nation may claim for entering into a conflict. It is used retrospectively to describe situations that arose before the term came into wide use, as well as being used to describe present-day situations—even those in which war has not been formally declared.

In formally articulating a casus belli, a government typically lays out its reasons for going to war, its intended means of prosecuting the war, and the steps that others might take to dissuade it from going to war. It attempts to demonstrate that it is going to war only as a last resort (ultima ratio) and that it has "just cause" for doing so. Modern international law recognizes only three lawful justifications for waging war: self-defense, defense of an ally required by the terms of a treaty, and approval by the United Nations.

Acts of the Apostles

The Acts of the Apostles (Ancient Greek: Πράξεις τῶν Ἀποστόλων, Práxeis tôn Apostólōn; Latin: Āctūs Apostolōrum), often referred to simply as Acts, is the fifth book of the New Testament; it tells of the founding of the Christian church and the spread of its message to the Roman empire.

Acts and the Gospel of Luke make up a two-part work, Luke–Acts, by the same anonymous author, usually dated to around 80-90 AD. The first part, the Gospel of Luke, tells how God fulfilled his plan for the world's salvation through the life, death and resurrection of Jesus of Nazareth, the promised Messiah. Acts continues the story of Christianity in the 1st century, beginning with Jesus' Ascension to Heaven. The early chapters, set in Jerusalem, describe the Day of Pentecost (the coming of the Holy Spirit) and the growth of the church in Jerusalem. Initially the Jews are receptive to the Christian message, but soon they turn against the followers of Jesus. Rejected by the Jews, under the guidance of the Apostle Peter the message is taken to the Gentiles. The later chapters tell of Paul's conversion, his mission in Asia Minor and the Aegean, and finally his imprisonment in Rome, where, as the book ends, he awaits trial.

World War I

World War I (WWI or WW1), also known as the First World War, or the Great War, was a global war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. Over 9 million combatants and 7 million civilians died as a result of the war (including the victims of a number of genocides), a casualty rate exacerbated by the belligerents' technological and industrial sophistication, and the tactical stalemate caused by trench warfare, a grueling form of warfare in which the defender held the advantage. It was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved.

The war drew in all the world's economic great powers, assembled in two opposing alliances: the Allies (based on the Triple Entente of the United Kingdom/British Empire, France and the Russian Empire) versus the Central Powers of Germany and Austria-Hungary. Although Italy was a member of the Triple Alliance alongside Germany and Austria-Hungary, it did not join the Central Powers, as Austria-Hungary had taken the offensive, against the terms of the alliance. These alliances were reorganised and expanded as more nations entered the war: Italy, Japan and the United States joined the Allies, while the Ottoman Empire and Bulgaria joined the Central Powers.

First World

The concept of the First World originated during the Cold War and included countries that were generally aligned with or on friendly terms with the United States (including all NATO countries) and were generally identified as non-theocratic democracies with primarily market-based economies. While there is no current consensus on an exact definition of the term, in modern usage, "First World country" generally implies a relatively wealthy, stable and functional non-theocratic democracy with a reasonably well educated population, or just any developed country.

During the Cold War, relationships between the First World and the Second World of Communist states were typically competitive, ideological, and occasionally hostile. Relationships of both these "Worlds" with "Third World" countries (i.e. all the rest) were normally positive in theory, while some were quite negative in practice (such as proxy war between client states). Since the dissolution of the Soviet Union and advances in communication technology, relations amongst the "Worlds" are not as rigid, although there are still marked disparities, with the First World generally having more influence, wealth, and access to information and technological innovations than the Second and Third Worlds.