The Doolittle Raid, 18 April 1942, was the first air raid by the United States to strike a Japanese home island (Honshū) during World War II. It demonstrated that Japan itself was vulnerable to Allied air attack and provided an expedient means for U.S. retaliation for Japan's attack on Pearl Harbor on 7 December 1941. The raid was planned and led by Lieutenant Colonel James "Jimmy" Doolittle. Doolittle would later recount in his autobiography that the raid was intended to cause the Japanese to doubt their leadership and to raise American morale:
The Japanese had been told they were invulnerable. An attack on the Japanese homeland would cause confusion in the minds of the Japanese people and sow doubt about the reliability of their leaders. There was a second, equally important, psychological reason for this attack...Americans badly needed a morale boost.
Sixteen B-25B Mitchell bombers were launched from the aircraft carrier USS Hornet deep within enemy waters. The plan called for them to hit military targets in Japan, and land in China. All of the aircraft were lost and 11 crewmen were either killed or captured. One of these B-25s landed in Soviet territory where its crew remained interned for more than a year. The entire crews of 13 of the 16 aircraft, and all but one of a 14th, returned to the United States or to Allied control. The raid caused little material damage to Japan, but succeeded in its goal of helping American morale. It also caused Japan to withdraw a carrier group from the Indian Ocean to defend their homeland and contributed to Japan's decision to attack Midway.
The April 1942 air attack on Japan, launched from the aircraft carrier Hornet and led by Lieutenant Colonel James H. Doolittle, was the most daring operation yet undertaken by the United States in the young Pacific War. Though conceived as a diversion that would also boost American and allied morale, the raid generated strategic benefits that far outweighed its limited goals.
The raid had its roots in a chance observation that it was possible to launch Army twin-engined bombers from an aircraft carrier, making feasible an early air attack on Japan. Appraised of the idea in January 1942, U.S. Fleet commander Admiral Ernest J. King and Air Forces leader General Henry H. Arnold greeted it with enthusiasm. Arnold assigned the technically-astute Doolittle to organize and lead a suitable air group. The modern, but relatively well-tested B-25B "Mitchell" medium bomber was selected as the delivery vehicle and tests showed that it could fly off a carrier with a useful bomb load and enough fuel to hit Japan and continue on to airfields in China.
The Pacific Theatre