Pearl Harbor and U.S. entry (December 1941)

On December 7, 1941, Japan launched a surprise attack on the U.S. Pacific Fleet at Pearl Harbor, Hawaii. The attack sank or damaged eight American battleships and killed about 2,400 Americans. The next day Congress declared war on Japan. Within days Germany and Italy declared war on the United States (in solidarity with Japan, their Axis partner). The war was now truly global.