10 World War II Battles Not Involving U.S.

How long did World War II last? For the United States, it started in 1941 when Japan attacked Pearl Harbor. For Germany, the United Kingdom, and France, it started in 1939 when they all declared war on each other over a treaty the latter two had with Poland. For the Soviet Union, it started in 1941 when Germany launched a sneak attack on the Bolshevik republic.