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:
Empire of Japan
Facing an oil embargo by the United States as well as dwindling domestic reserves, the Japanese government decided to execute a plan developed by Isoroku Yamamoto to attack the United States Pacific Fleet in Hawaii. The Imperial Japanese Navy made its surprise attack on Pearl Harbor, Oahu, Hawaii, on Sunday morning, December 7, 1941. American forces sustained significant losses. The primary objective of the attack was to incapacitate the United States long enough for Japan to establish its long-planned Southeast Asian empire and defensible buffer zones. The American public saw the attack as a treacherous act and rallied against the Japanese. Four days later, Adolf Hitler of Germany, and Benito Mussolini of Italy declared war on the United States, merging the separate conflicts. The United States entered the European Theatre and Pacific Theater in full force, thereby bringing the United States to World War II on the side of the Allies.