A U.S. sailor salutes during a ceremony commemorating the 72nd anniversary of the attack on Pearl Harbor Dec. 7, 2013, at the World War II Valor in the Pacific National Monument at Joint Base Pearl Harbor-Hickam, Hawaii. The morning of Dec. 7, 1941, Japanese bombers staged a surprise attack on U.S. military forces in Hawaii. The day after the attack, before a joint session of Congress, President Franklin D. Roosevelt asked for a declaration of war against Japan and the U.S. officially entered World War II. (U.S. Navy photo by Mass Communication Specialist 3rd Class Diana Quinlan/Released)