World war

A world war is a war affecting most of the world’s most powerful and populous countries. World wars span multiple countries on multiple continents, with battles fought in multiple theaters. The term is usually applied to the two conflicts of unprecedented scale that occurred during the 20th century: World War I (1914–1918) and World War II (1939–1945). However, it is also sometimes applied to earlier wars and to a hypothetical future war.

Air force

Allies of World War II