|Battle of Midway|
|Prelude to battle|
|Attacks on the Japanese fleet|
|Discovery of sunken vessels|
Midway Atoll, several months before the battle. Eastern Island (with the airfield) is in the foreground, and the larger Sand Island is in the background to the west.
The Japanese operation, like the earlier attack on Pearl Harbor, was aimed at the elimination of the United States as a strategic Pacific power, 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 for Japan.
The Japanese plan was designed to lure the United States' few remaining 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.
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, particularly the four fleet carriers and their aircrews, permanently weakened the Imperial Japanese Navy. Japan was unable to keep pace with American shipbuilding and pilot training programs in providing replacements.
U.S. Douglas SBD-3 Dauntless dive bombers about to attack the burning cruiser Mikuma for the third time.
Yamamoto's primary strategic concern was the elimination of America's remaining carrier forces, the principal obstacle to the overall campaign. This concern was acutely heightened by the Doolittle Raid on Tokyo (18 April 1942) by USAAF B-25s, launching from USS Hornet. The raid, while militarily insignificant, was a severe psychological shock to the Japanese and proved the existence of a gap in the defenses around the Japanese home islands. Sinking America's aircraft carriers and seizing Midway, the only strategic island besides Hawaii in the east Pacific, was seen as the only means of nullifying this threat. Yamamoto reasoned an operation against the main carrier base at Pearl Harbor would induce the U.S. forces to fight. However, given the strength of American land-based air power on Hawaii, he judged the powerful American base could not be attacked directly.Instead, he selected Midway, at the extreme northwest end of the Hawaiian Island chain, some 1,300 miles (2,100 km) from Oahu. Midway was not especially important in the larger scheme of Japan's intentions, but the Japanese felt the Americans would consider Midway a vital outpost of Pearl Harbor and would therefore strongly defend it. The U.S. did consider Midway vital; after the battle, establishment of a U.S. submarine base on Midway allowed submarines operating from Pearl Harbor to refuel and reprovision, extending their radius of operations by 1,200 miles (1,900 km). An airstrip on Midway served as a forward staging point for bomber attacks on Wake Island.