Battle of Midway.

The Battle of Midway in the Pacific Theater of Operations was one of the most important naval battles of World War II.  Between 4 and 7 June 1942, only six months after Japan's attack on Pearl Harbor, and one month after the Battle of the Coral Sea, the United States Navy (USN), under Admirals Chester W. Nimitz, Frank Jack Fletcher, and Raymond A. Spruance decisively defeated an attack by the Imperial Japanese Navy(IJN), under Admirals Isoroku Yamamoto, Chuichi Nagumo, and Nobutake Kondo on Midway Atoll, inflicting irreparable damage on the Japanese fleet. Military historian John Keegan called it "the most stunning and decisive blow in the history of naval warfare." It was Japan's first naval defeat since the Battle of Shimonoseki Straits in 1863.

The Japanese operation, like the earlier attack on Pearl Harbor, sought 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. The Japanese hoped that another demoralizing defeat would force the U.S. to capitulate in the Pacific War and thus ensure Japanese dominance in the Pacific. 

The Japanese plan was to lure the United States' aircraft carriers into a trap.  The Japanese also intended to occupy Midway as part of an overall plan to extend their defensive perimeter in response to theDoolittle air raid on Tokyo. This operation was also considered preparatory for further attacks against Fiji, Samoa, and Hawaii itself.

The plan was handicapped by faulty Japanese assumptions of the 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—Akagi, Kaga, Soryu and Hiryu, all part of the six-carrier force that had attacked Pearl Harbor six months earlier—and a heavy cruiser were sunk at a cost of one American aircraft carrier and a destroyer. After Midway and the exhausting attrition of theSolomon Islands campaign, Japan's shipbuilding and pilot training programs were unable to keep pace in replacing their losses, while the U.S. steadily increased its output in both areas.