Introduced on May 8, 1944, the Boeing B-29 Superfortress was the answer to this need for longer flights and more ordnance-carrying ability. In response to the need for a better bomber, the military turned to Boeing, a well-known name in American aviation. The B-25 bombers used for the assault were only capable of a one-way trip because of their lower fuel capacity. One early indicator of this was the Doolittle Raid on Tokyo on April 18, 1942. To answer this challenge, the Americans needed to greatly expand its own military power, including the range and capacity of its bombers. The forces of Imperial Japan attacked the naval base on the island of Oahu in an attempt to cripple the Pacific Fleet. The attack on Pearl Harbor on Decemforced the United States into military conflict with a powerful and bold opponent.