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:
Prisoner of war
Allied POW camps and ship-transports were sometimes accidental targets of Allied attacks. The number of deaths which occurred when Japanese "hell ships"—unmarked transport ships in which POWs were transported in harsh conditions—were attacked by US Navy submarines was particularly high. Gavan Daws has calculated that "of all POWs who died in the Pacific War, one in three was killed on the water by friendly fire". Daves states that 10,800 of the 50,000 POWs shipped by the Japanese were killed at sea while Donald L. Miller states that "approximately 21,000 Allied POWs died at sea, about 19,000 of them killed by friendly fire."