<P> The U.S. learned of the Japanese plan through signals intelligence, and sent two United States Navy carrier task forces and a joint Australian - American cruiser force to oppose the offensive . These were under the overall command of American Admiral Frank J. Fletcher . </P> <P> On 3--4 May, Japanese forces successfully invaded and occupied Tulagi, although several of their supporting warships were sunk or damaged in surprise attacks by aircraft from the U.S. fleet carrier Yorktown . Now aware of the presence of U.S. carriers in the area, the Japanese fleet carriers advanced towards the Coral Sea with the intention of locating and destroying the Allied naval forces . Beginning on 7 May, the carrier forces from the two sides engaged in airstrikes over two consecutive days . On the first day, the U.S. sank the Japanese light carrier Shōhō; meanwhile, the Japanese sank a U.S. destroyer and heavily damaged a fleet oiler (which was later scuttled). The next day, the Japanese fleet carrier Shōkaku was heavily damaged, the U.S. fleet carrier Lexington critically damaged (and later scuttled), and Yorktown damaged . With both sides having suffered heavy losses in aircraft and carriers damaged or sunk, the two forces disengaged and retired from the battle area . Because of the loss of carrier air cover, Inoue recalled the Port Moresby invasion fleet, intending to try again later . </P> <P> Although a tactical victory for the Japanese in terms of ships sunk, the battle would prove to be a strategic victory for the Allies for several reasons . The battle marked the first time since the start of the war that a major Japanese advance had been checked by the Allies . More importantly, the Japanese fleet carriers Shōkaku and Zuikaku--the former damaged and the latter with a depleted aircraft complement--were unable to participate in the Battle of Midway the following month, while Yorktown did participate, ensuring a rough parity in aircraft between the two adversaries and contributing significantly to the U.S. victory in that battle . The severe losses in carriers at Midway prevented the Japanese from reattempting to invade Port Moresby from the ocean and helped prompt their ill - fated land offensive over the Kokoda trail . Two months later, the Allies took advantage of Japan's resulting strategic vulnerability in the South Pacific and launched the Guadalcanal Campaign; this, along with the New Guinea Campaign, eventually broke Japanese defenses in the South Pacific and was a significant contributing factor to Japan's ultimate defeat in World War II . </P> <P> On 7 December 1941, using aircraft carriers, Japan attacked the U.S. Pacific Fleet at Pearl Harbor, Hawaii . The attack destroyed or crippled most of the Pacific Fleet's battleships and brought the United States into the war . In launching this war, Japanese leaders sought to neutralize the American fleet, seize territory rich in natural resources, and obtain strategic military bases to defend their far - flung empire . At the same time that they were attacking Pearl Harbor, the Japanese attacked Malaya, causing Britain, Australia, and New Zealand to join the United States in the war against Japan . In the words of the Imperial Japanese Navy (IJN) Combined Fleet's "Secret Order Number One", dated 1 November 1941, the goals of the initial Japanese campaigns in the impending war were to "(eject) British and American strength from the Netherlands Indies and the Philippines, (and) to establish a policy of autonomous self - sufficiency and economic independence ." </P>

Why was the battle of the coral sea significant for the allies (4 points)