The War Becomes Global: Pearl Harbor, North Africa, and the Pacific

The Japanese attack on Pearl Harbor on 7 December 1941 brought the United States into the war immediately, and within days, on 11 December, Germany and Italy declared war on America as well, unifying the European, African, Asian, and Pacific fronts into a single global conflict. The Allies had already agreed on a strategy of "Europe First," judging Germany the more dangerous threat, while twenty-six nations signed the Declaration by United Nations in January 1942, forming the Grand Alliance and binding themselves not to sign a separate peace with the Axis.