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:
Pacific War
In the early hours of 7 December (Hawaiian time), Japan launched a major surprise carrier-based air strike on Pearl Harbor without explicit warning, which crippled the US Pacific Fleet, leaving eight American battleships out of action, 188 American aircraft destroyed, and 2,403 Americans dead. At the time of the attack, the US was not officially at war anywhere in the world as the Japanese embassy failed to decipher and deliver the Japanese ultimatum to the American government before noon December 7 (Washington time), which means that the people killed or property destroyed at Pearl Harbor by the Japanese attack had a non-combatant status. The Japanese had gambled that the United States, when faced with such a sudden and massive blow, would agree to a negotiated settlement and allow Japan free rein in Asia. This gamble did not pay off. American losses were less serious than initially thought: the American aircraft carriers, which would prove to be more important than battleships, were at sea, and vital naval infrastructure (fuel oil tanks, shipyard facilities, and a power station), submarine base, and signals intelligence units were unscathed. Japan's fallback strategy, relying on a war of attrition to make the US come to terms, was beyond the IJN's capabilities.