Japanese war crimes
The U.S. officially classified all 3,649 military and civilian casualties and destruction of military property at Pearl Harbor as non-combatants as there was no state of war between the U.S. and Japan when the attack occurred. Joseph B. Keenan, the chief prosecutor in the Tokyo Trials, says that the attack on Pearl Harbor not only happened without a declaration of war but was also a treacherous and deceitful act. In fact, Japan and the U.S. were still negotiating for a possible peace agreement which kept U.S. officials very distracted when Japanese planes bombed Pearl Harbor. Keenan explained the definition of a war of aggression and the criminality of the attack on Pearl Harbor:
Attack on Pearl Harbor
The day after the attack, Roosevelt delivered his famous Infamy Speech to a Joint Session of Congress, calling for a formal declaration of war on the Empire of Japan. Congress obliged his request less than an hour later. On December 11, Germany and Italy declared war on the United States, even though the Tripartite Pact did not require it. Congress issued a declaration of war against Germany and Italy later that same day. The UK actually declared war on Japan nine hours before the U.S. did, partially due to Japanese attacks on Malaya, Singapore and Hong Kong, and partially due to Winston Churchill's promise to declare war "within the hour" of a Japanese attack on the United States.
The attack was an initial shock to all the Allies in the Pacific Theater. Further losses compounded the alarming setback. Japan attacked the Philippines hours later (because of the time difference, it was December 8 in the Philippines). Only three days after the attack on Pearl Harbor, the battleships "Prince of Wales" and "Repulse" were sunk off the coast of Malaya, causing British Prime Minister Winston Churchill later to recollect "In all the war I never received a more direct shock. As I turned and twisted in bed the full horror of the news sank in upon me. There were no British or American capital ships in the Indian Ocean or the Pacific except the American survivors of Pearl Harbor who were hastening back to California. Over this vast expanse of waters Japan was supreme and we everywhere were weak and naked".
Throughout the war, Pearl Harbor was frequently used in American propaganda.