By June 1942, the Japanese controlled most of the Pacific area, Malaya. Parts of Burma and Thailand, Indo-China, Hong Kong, the Dutch East Indies and the Philippines. However, the navies of America and Japan fought two epic battles in April and June that changed the course of World War II. Victories in the Coral Sea and at Midway Island shifted the advantage to the Allies in the Pacific.

The four-day Battle of the Coral Sea started when the Americans decoded Japanese invasion plans for Port Moresby, New Guinea, and Tulagi, in the Solomon Islands. America sent a naval force to stop the Japanese troops. The enemy ships never met each other, but from May 2 through May 6, both fleets attacked each other with waves of fighter planes and bombers. The Japanese lost 70 planes and its light carrier Shoho. The American losses included 66 planes and the aircraft carrier Lexington, a vital oceangoing carrier. Although victorious in terms of ship tonnage sunk, Japan lost too many fighter pilots to continue with the invasions. Thus its southward advances were halted.

A month later, American triumphed again at Midway. Once again they became aware of the Japanese plans, and lay in wait for the huge fleet of 86 warship sent by Japan to attack the tiny island in the Pacific. On June 3, the Japanese launched an attack on the two westernmost Aleutian islands, Kiska and Attu (the only American soil to be occupied by the Japanese during the war), in order to the divert the Americans' attention. The next day, a swarm of Japanese carrier-launched planes bombed Midway. The Americans responded with three consecutive air attacks on the Japanese, each a failure. But on June 5, the Americans bombing raid sank three Japanese aircraft carriers. His fleet devastated, Japanese admiral Yamamoto retreated west. The Japanese lost four aircraft carriers, a cruiser, 332 planes and 3500 lives; the Americans: one aircraft carrier, a destroyer, 147 planes and 307 lives.

Although the bloodiest battles of the Pacific were yet to come, the Japanese army never recovered from these defeats.