User: How long did World War 2 last?
Assistant: World War II or the Second World War, often abbreviated as WWII or WW2, was a global conflict that lasted from 1939 to 1945. The vast majority of the world's countries, including all of the great powers, fought as part of two opposing military alliances: the Allies and the Axis. The Axis included Germany, Italy, and Japan as the main combatants, while the Allies consisted of France, Great Britain, the United States, the Soviet Union, and, to some extent, China.