On June 13, 1944 the press reported that President Roosevelt had been presented with a letter-opener made out of a Japanese soldier's arm bone by Francis E. Walter, a Democratic congressman...

May 22, 1944 Life Magazine Picture of the Week, "Arizona war worker writes her Navy boyfriend a thank-you-note for the Jap skull he sent her"
Как я понимаю, эта гуманистическая традиция проявилась не так давно во время американской оккупации Ирака.