International relations (1919–1939) covers the main interactions shaping world history in this era, known as the Interwar Period, with emphasis on diplomacy and economic relations. The coverage here follows the diplomatic history of World War I and precedes the diplomatic history of World War II. The important stages of interwar diplomacy and international relations included resolutions of wartime issues, such as and boundaries; American involvement in European finances and disarmament projects; the of the League of Nations; the ; the between the Soviet Union and the capitalist world; peace and disarmament efforts; responses to the Great Depression starting in 1929; the collapse of world trade; the collapse of democratic regimes one by one; the growth of economic autarky; Japanese aggre