War Expands: The Pacific and Beyond

The militarist Japanese government decided to settle matters once and for all with the United States, which was blocking Japan’s access to technology and resources in an attempt to stop its expansionism. On December 7, 1941, it launched an all-out attack on the United States at Pearl Harbor in Hawaii and then decimated a fleet of airplanes in the Philippines. Roosevelt immediately summoned the U.S. Congress to declare war on Japan. By the spring of 1942, the Japanese had conquered Guam, the Philippines, Malaya, Burma, Indonesia, Singapore, and much of the southwestern Pacific. Like Hitler’s early conquests, the Japanese victories strengthened the military’s confidence: “The era of democracy is finished,” the foreign minister announced, marketing Emperor Hirohito as the monarch who would liberate Asians everywhere.

Germany quickly declared war on the United States; Mussolini followed suit. The United States was not prepared for a prolonged struggle at the time, partly because isolationist sentiment remained strong. Its armed forces numbered only 1.6 million, and no plan existed for producing the necessary guns, tanks, and airplanes. In addition, the United States and the Soviet Union mistrusted each other. Yet despite these obstacles to cooperation, Hitler’s four enemies came together in the Grand Alliance of Great Britain, the Free French (an exile government in London led by General Charles de Gaulle), the Soviet Union, and the United States along with twenty other countries—known collectively as the Allies. Against the Axis powers—Germany, Italy, and Japan—the Allies had advantages: greater manpower and resources, access to goods from global empires, and Britain’s traditional naval strength and its experience in combat on many continents. Allied leaders worked hard to wage effective war against the Axis powers, whose rulers were fanatically committed to global conquest at any price.