A declaration of war is a formal act by which one nation goes to war against another. A declaration is usually an act of delivering a performative speech (not to be confused with a mere ''speech'') or the presentation of a signed document by an authorized party of a national government in order to create a state of war between two or more sovereign states. In the context of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

, the official international protocol for declaring war was defined in the

Hague Convention of 1907 The Hague Conventions of 1899 and 1907 are a series of international treaties and declarations negotiated at two international peace conferences at The Hague in the Netherlands. Along with the Geneva Conventions, the Hague Conventions were amo ...

(or Hague II).''On the Opening of Hostilities''
1907;

Yale Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the wor ...

Law School Library; retrieved March 2014. For the diplomatic maneuvering behind these events, which led to hostilities between nations, see

Diplomatic history of World War I The diplomatic history of World War I covers the non-military interactions among the major players during World War I. For the domestic histories of participants see home front during World War I. For a longer-term perspective see international re ...

List of war declarations

Below is a table showing the outbreaks of wars between nations which occurred during World War I. Indicated are the dates (during the immediate build-up to, or during the course of, World War I) from which a ''

de facto ''De facto'' ( ; , "in fact") describes practices that exist in reality, whether or not they are officially recognized by laws or other formal norms. It is commonly used to refer to what happens in practice, in contrast with ''de jure'' ("by la ...

'' state of war existed between nations. The table shows both the initiator states and the state at which the declaration of war was aimed. Events listed include those in which there were a simple diplomatic breaking of relations that did not involve any physical attack, as well as those involving overt declarations or acts of aggression.

References

{{Reflist, 2

declaration Declaration may refer to: Arts, entertainment, and media Literature * ''Declaration'' (book), a self-published electronic pamphlet by Michael Hardt and Antonio Negri * ''The Declaration'' (novel), a 2008 children's novel by Gemma Malley Music ...

List of war declarations

See also

References