The years of World War II were traumatic for Kuniyoshi. Immediately after the Japanese bombing of Pearl Harbor on December 7, 1941, the US government reclassified Kuniyoshi as an “enemy alien,” impounded his bank account, confiscated his camera and binoculars, and restricted his travel outside New York City. Nonetheless, he remained a fervent believer in the democratic system and a fierce opponent of Japanese militarism. He worked actively to support the Allies, recording radio broadcasts to the people of Japan for Voice of America and making propaganda drawings for the Office of War Information.
Many of Kuniyoshi's war drawings are brutal indictments of Japanese atrocities. Hanged shows corpses in trees that recall Goya’s Disasters of War series. Clean Up This Mess depicts a huge hand holding a garbage bag stuffed with the Japanese flag, bloody samurai swords, and an octopus, ready to be dropped into the void. The largest and most powerful is Torture, intended for a poster, showing the muscled torso of a man wrestling with shackles that painfully bind his hands, all in black and white except for the red welts on his skin.