The Doolittle Raid, also known as the Tokyo Raid, was an air raid on 18 April 1942 by the United States on the Japanese capital Tokyo and other places on Honshu. It was the first air operation to strike the Japanese archipelago. It demonstrated that the Japanese mainland was vulnerable to American air attack, served as retaliation for the attack on Pearl Harbor. The raid caused negligible material damage to Japan, but it had major psychological effects. In the United States, it raised morale. In Japan, it raised doubt about the ability of military leaders to defend the home islands, but the bombing and strafing of civilians also steeled Japanese resolve to gain retribution, and this was exploited for propaganda purposes.