When World War II started in 1939, it was primarily the French and British alliance fighting against the German and Soviet Union alliance. Within a few years, however, the war would become much more global. After Germany had defeated France Italy entered the war on the side of the Germans, and grabbed part of France for Italy. Hitler attempted to make an alliance with Franco, the dictator of Spain, but Franco had no real interest to enter the war. Another “neutral” power was the United States. While technically neutral, Franklin Roosevelt desperately wanted to get involved in the war against Germany, but according to polls, 80% of Americans preferred a non-interventionist policy. Instead, Roosevelt gave supplies to Britain and drew up the Atlantic Charter, a war aims document, before the United States had even entered the war.
Japan had signed a pact of non-aggression with the Soviet Union during the first years of World War II. The United States had positioned a Navy outpost at Pearl Harbor to kind of dangle the American fleet in front of them. Shortly before the attack on Pearl Harbor, the United States stopped selling the Japanese oil. The Japanese and the Americans had both been pushing forward into the Pacific to create a bigger empire. When the Japanese bombed Pearl Harbor Roosevelt declared war on Japan but what he still really wanted was a war with Germany. In fact, the war department had no real plans for a war with Japan because they had been so fixated on Germany. Luckily for Roosevelt, however, the Germans declared war on the United States four days after Pearl Harbor on December 11, 1941. At this point, World War II had reached a global scale.