The Japanese operation, like the earlier attack on Pearl Harbor, aimed to eliminate the United
States as a strategic power in the Pacific, thereby giving Japan a free hand in establishing its
Greater East Asia Co-Prosperity Sphere. It was hoped another demoralizing defeat would force
the U.S. to negotiate an end to the Pacific War on conditions favorable to Japan.

The Japanese plan was to lure the United States’ few remaining aircraft carriers into a trap. The
Japanese also intended to occupy Midway Atoll as part of an overall plan to extend their defensive
perimeter in response to the Doolittle Raid. This operation was considered preparatory for further
attacks against Fiji and Samoa.

The plan was handicapped by faulty Japanese assumptions of American reaction and poor initial
dispositions. Most significantly, American codebreakers were able to determine the date and
location of the attack, enabling the forewarned U.S. Navy to set up an ambush of its own. Four
Japanese aircraft carriers and a heavy cruiser were sunk in exchange for one American aircraft
carrier and a destroyer. The heavy losses in carriers and aircrews permanently weakened the
Imperial Japanese Navy. Japan’s shipbuilding and pilot training programs were unable to keep
pace in replacing their losses, while the U.S. steadily increased output in both areas.