In 1939 Adolf Hitler and Soviet leader Joseph Stalin had signed a pact not to attack each other’s countries. But Hitler had no intention of abiding by it. Early the morning of June 22, 1941, a huge force of German tanks and airplanes invaded the Soviet Union, crossing a 1,900-mile (3,058-km) border extending from the Baltic Sea to the Black Sea. The surprise invasion was called Operation Barbarossa and involved 3 million troops.
Following the German successes elsewhere in Europe, Hitler was confident of victory over the Soviet Union. “You only have to kick in the door and the whole rotten structure will come crashing down,”4 he said. Hitler was determined to crush Communism in the Soviet Union. He believed Communists had been partly to blame for Germany’s defeat in World War I and that Communism was linked to Jews, whom he hated.
German forces rapidly advanced across the Soviet Union. By December they were only 15 miles (24 km) from the capital, Moscow, and were laying siege to Leningrad. Just when it seemed as if the Soviet Union would fall to Hitler, the bitterly cold weather and a massive counterattack drove the Germans back from Moscow. Operation Barbarossa, one of the largest military operations in history, was a failure.
Hideki Tojo became prime minister of Japan in October 1941 and committed his country to an aggressive course. Even while negotiations continued with the United States to preserve peace, Japan was secretly planning for war. To prevent the Americans from interfering with their assault on Southeast Asia, the Japanese decided to attack.
The morning of December 7, 1941, 366 Japanese planes, launched in two waves from six aircraft carriers, attacked the American naval base at Pearl Harbor, Hawaii. The Japanese also used midget submarines that fired torpedoes at the American ships in the harbor. There was no declaration of war, and the Americans were taken by surprise. The attack sank or damaged eight American battleships and one training ship and destroyed a large number of American aircraft, mostly on the ground. Thousands of Americans were killed or wounded. Japan lost only 29 planes and 55 men in the attack.
Japan’s invasions to the south met with little opposition in the weeks that followed Pearl Harbor. Japan attacked the British-held territories of Hong Kong, Singapore, and Malaya, the Dutch East Indies, and the American-held Philippines. The United States and Britain, along with several other countries, declared war on Japan. Germany and Italy, Japan’s allies, responded by declaring war on the United States. The war was now truly global.
By 1942 the Axis powers controlled much of Europe and Asia.