Battle of Leyte Gulf

The Battle of Leyte Gulf (Japanese: レイテ沖海戦, romanized: Reite oki Kaisen, lit. 'Leyte Open Sea Naval Battle') 23–26 October 1944, was the largest naval battle of World War II and by some criteria the largest naval battle in history, with over 200,000 naval personnel involved.

By late 1944, Japan possessed fewer capital ships (aircraft carriers and battleships) than the Allied forces had total aircraft carriers in the Pacific, which underscored the disparity in force strength at that point in the war. After the catastrophic Battle of the Philippine Sea in June 1944, senior Japanese military leaders understood that their remaining naval forces were incapable of achieving a strategic victory against the Allies. However, the Japanese general staff believed that continuing to contest Allied offensives at sea was necessary to deter an invasion of mainland Japan and to give the Japanese navy an opportunity to use its remaining strength. As a result, the Imperial Japanese Navy (IJN) mobilized nearly all of its remaining major naval vessels in an attempt to repel the Allied invasion of the Philippines, but it was defeated by the U.S. Navy's Third and Seventh Fleets.

The battle consisted of four main engagements (the Battle of the Sibuyan Sea, the Battle of Surigao Strait, the Battle off Cape Engaño, and the Battle off Samar) and several lesser actions. Allied forces announced the end of organized Japanese resistance on the island of Leyte at the end of December.

It was the first battle in which Japanese aircraft carried out organized kamikaze attacks, and it was the last-ever battle between battleships. The Japanese navy suffered crippling losses and did not sail in comparable force for the remainder of the war, as most of its vessels were stranded in port for lack of fuel.

The Allied campaigns of August 1942 to early 1944 had pushed Japanese forces from many of their island bases in the south and central Pacific Ocean, while isolating many of their other bases (most notably in the Solomon Islands, Bismarck Archipelago, Admiralty Islands, New Guinea, Marshall Islands, and Wake Island). In June 1944 a series of American amphibious landings supported by the U.S. Fifth Fleet's Fast Carrier Task Force captured most of the Mariana Islands (but bypassing Rota). This offensive breached Japan's strategic inner defense perimeter and provided the Americans a base from which long-range Boeing B-29 Superfortress bombers could attack the Japanese home islands.

The Japanese attempted to interdict American landings in the Marianas during the Battle of the Philippine Sea in July 1944. In the course of the battle, the U.S. Navy destroyed three Japanese aircraft carriers, damaged various other IJN ships, and shot down approximately 600 Japanese aircraft. This left the Japanese Navy with little carrier-borne air power and few experienced pilots. However, the considerable land-based air power that the Japanese had amassed in the Philippines was considered too dangerous to bypass by many high-ranking officers outside the Joint Chiefs of Staff, including Admiral Chester Nimitz.

The next logical step was to cut Japan's supply lines to Southeast Asia, depriving the Japanese empire of fuel and other critical supplies. However, there were two different plans for doing so. Admiral Ernest J. King, other members of the Joint Chiefs of Staff, and Admiral Nimitz favored blockading Japanese forces in the Philippines and invading Formosa (Taiwan), while U.S. Army General Douglas MacArthur, wishing to fulfill his 1942 promise to "return" to the Philippines, championed an invasion of the islands.

While Formosa could also serve as a base for an invasion of mainland China, which MacArthur felt was unnecessary, it was also estimated that an invasion of the island would require about twelve divisions from the Army and Marines. Meanwhile, the Australian Army, spread thin by engagements in the Solomon Islands, New Guinea, the Dutch East Indies and various other Pacific islands, would not have been able to spare any troops for such an operation. As a result, an invasion of Formosa, or any operation requiring much larger ground forces than were available in the Pacific in late 1944, would be delayed until the defeat of Germany made the necessary manpower available.