World War II began in 1939 with Germany’s invasion of Poland. After they finished their attack in eastern Europe the Germans moved west, taking control of Belgium, a northern part of France, Denmark, Norway and choice pieces of Czechoslovakia and Lithuania. The Italians got involved not long after, attacking France in 1940 and taking a slice of their territory. Meanwhile Germany and Britain were locked in fierce combat, with Germany violating the Versailles treaty by using air force combat and bombing against the Brits. Operation Barbarossa (Germany’s attempt to invade the Soviets) was launched after a Non Aggression pact had been created between the soviets and the Japanese. But Germany underestimated the harshness of a Russian winter, and their invasion plan failed.
In the US tensions between the Americans and Japanese had caused President Roosevelt to cut off any and all trading ties between the two countries. To add insult to injury Roosevelt stuck his pacific fleet in the middle of pearl harbor, an obvious sign of political aggression. On December 7th this tactic resulted in the infamous bombing of pearl harbor, a Japanese air strike against the US. Roosevelt declared war against Japan, but he wasn’t in a place to declare war against Germany. It turns out he wouldn’t have to, as four days later on December 11th Hitler declared war against America. From there nearly every global superpower got involved with the war, as Hitlers ruthlessness and power hunger was too much for the countries of the world to ignore.