World War I: World War I

1915, Allied expedition in World War I for the purpose of gaining control of the Dardanelles and Bosporus straits, capturing Constantinople, and opening a Black Sea supply route to Russia MORE

Agreement between two or more states to come to each other's assistance in the event of war. Alliances were criticized after World War I as having contributed to the outbreak of war, but the North Atlantic Treaty Organization (NATO) has been a major part of the post-1945 structure of international relations (as was the Warsaw Pact until its dissolution 1991). MORE

Person captured in war, who has fallen into the hands of, or surrendered to, an opponent MORE

Offence (such as murder of a civilian or a prisoner of war) that contravenes the internationally accepted laws governing the conduct of wars, particularly the Hague Convention of 1907 and the Geneva Convention of 1949 MORE

International organization formed after World War I to solve international disputes by arbitration. Established in Geneva, Switzerland, in 1920, the League included representatives from states throughout the world, but was severely weakened by the US decision not to become a member, and had no power to enforce its decisions. MORE

In politics, the theory that the best way of ensuring international order is to have power so distributed among states that no single state is able to achieve a dominant position MORE

Any of various gases sometimes used in warfare or riot control because of their poisonous or corrosive nature MORE

The navy of Britain; In World War I its main task was to protect shipping from submarine attack. MORE

A treaty that brought a formal end to the First World War MORE