The United States immediately declared war on Japan. One day later, on December 7, 1941, Japan (one of the Axis powers) bombed Pearl Harbor, Hawaii.

On December 6, 1941, Soviet troops launched a significant counteroffensive that drove German forces permanently from the outskirts of Moscow. During the summer and autumn of 1941, German troops advanced deep into the Soviet Union, but stiffening Red Army resistance prevented the Germans from capturing the key cities of Leningrad and Moscow. Soviet leader Joseph Stalin then became a major wartime Allied leader, in opposition to Nazi Germany and its Axis allies.

In June and July 1941, the Germans also occupied the Baltic states. From July 10 to October 31, 1940, the Nazis waged, and ultimately lost, an air war over England, known as the Battle of Britain.Īfter securing the Balkan region by invading Yugoslavia and Greece on April 6, 1941, the Germans and their allies invaded the Soviet Union on June 22, 1941, in direct violation of the German-Soviet Pact. Italy, a member of the Axis (countries allied with Germany), joined the war on June 10, 1940.

With German encouragement, the Soviet Union occupied the Baltic states in June 1940 and formally annexed them in August 1940. On June 22, 1940, France signed an armistice with Germany, which provided for the German occupation of the northern half of the country and permitted the establishment of a collaborationist regime in the south with its seat in the city of Vichy. On May 10, 1940, Germany began its assault on western Europe by invading the Low Countries (Netherlands, Belgium, and Luxembourg), which had taken neutral positions in the war, as well as France. The relative lull in fighting which followed the defeat of Poland ended on April 9, 1940, when German forces invaded Norway and Denmark. Within a month, Poland was defeated by a combination of German and Soviet forces and was partitioned between Nazi Germany and the Soviet Union. Britain and France responded by declaring war on Germany on September 3. 1939Īfter securing the neutrality of the Soviet Union (through the August 1939 German-Soviet Pact of nonaggression), Germany started World War II by invading Poland on September 1, 1939. The realization of German dominance in Europe, its leaders calculated, would require war. Still reeling from Germany's defeat in World War I, Hitler's government envisioned a vast, new empire of 'living space' ( Lebensraum) in eastern Europe. World War II: Maps The Holocaust took place in the broader context of World War II.

World's largest tank battle