A rout by the US in an air battle around Taiwan led Japan to adopt desperate tactics in World War II's final months

• On October 12, 1944, US carrier planes kicked off days of raids against Japanese forces on Formosa.
• The island, now called Taiwan, was a hub in a network of Japanese bases around the northwest Pacific.

At 5:44 a.m. on October 12, 1944, hundreds of US Navy fighter aircraft took off from their carriers roughly 50 miles to 90 miles east of Formosa, the island now known as Taiwan.

Their sortie, part of a plan to degrade and destroy Japanese airpower on the island, would be the first of thousands over the next three days.

It was the culmination of a massive diversionary effort that saw the carriers and their escorts, assigned to the Navy's Task Force 38, sail from their anchorage in Ulithi Atoll to southern Japan, then to Formosa, and then to the Philippines.

Their goal was to destroy as much of Japan's air and naval strength before US troops landed on the Philippine island of Leyte.

TF 38 would inflict massive losses on the Japanese, which in turn would help ensure a US victory off the coast of Leyte in what was history's largest naval battle.

A diversion

The strategic situation in the Pacific had turned decisively in the Allies' favor by fall 1944.

Devastating losses in the battles of Midway and the Philippine Sea hindered Japan's ability to conduct carrier operations, and the US's island-hopping campaign had moved within striking distance of the Philippines.

But Japan's air and naval power were still major threats, and to ensure the Philippines could be liberated, they had to be degraded, if not eliminated.

By 1944, Japanese military leaders recognized their situation and devised a plan to prepare for US invasions of Japanese-held territory.

Called "Sho-Go," or Operation Victory, the plan involved drawing the main US fleet into a kill zone and then destroying it with combined air and naval attacks. "Sho-1" referred to the defense of the Philippines, while "Sho-2" referred to Formosa.

The latter island was central to the Japanese plan.

Colonized by the Japanese in 1895, Formosa was one of Japan's most important air and naval outposts, and a key hub in a network of bases stretching from Iwo Jima, through the Japanese home islands and Korea, and then down through eastern China to Taiwan and Luzon in the Philippines.

The American plan was grand but simple. TF 38, made up of four carrier task groups, would sail toward Okinawa, launch diversionary strikes, then turn and focus on destroying Taiwan's airfields while drawing out Japanese aircraft from Japan's home islands.

Under the command of Adm. William Halsey, TF 38's four carrier task groups comprised 17 aircraft carriers, six battleships, 14 cruisers, and 58 destroyers. TF-38's more than 1,000 carrier aircraft would face an even larger number of Japanese planes.

'Knock-down, drag-out fight'

After its diversionary strikes on Okinawa on October 10, TF 38 sailed south and struck Luzon to further obscure its true intentions. The Japanese, understanding that the core of the US Navy's strength in the Pacific was now nearby, initiated the aerial component of Sho-1 and Sho-2.

The crux of the operation began on October 12. On the first day alone, US planes flew 1,378 sorties. US carrier aircraft swarmed over airfields on Formosa, destroying runways, hangars, and barracks. US planes battled Japanese aircraft from Formosa and their reinforcements from other Japanese-held islands.

The combat was intense and extensive. By the end of the first strike, one-third of the fighters from Japan's Sixth Base Air Force were destroyed while 48 US planes were lost. Japanese attempts to attack the carriers were fruitless, with 42 more Japanese planes shot down trying to conduct attack runs.

"Our fighters were nothing but so many eggs thrown at the stone wall of the indomitable enemy formation," Vice Adm. Shigeru Fukudome, commander of the Sixth Base Air Force, said later.

October 13 saw 974 sorties in which US planes attacked previously unknown airfields. This time, however, the Japanese managed to strike back, hitting the cruiser USS Canberra with a torpedo, killing 23 and causing major damage.

On October 14, after the last carrier strikes on Taiwan, the cruiser USS Houston was also hit by a torpedo and similarly damaged.

With no sign of the Japanese Navy and their inland targets destroyed, TF 38 headed south toward the Philippines. With the damaged Canberra and Houston in tow, the task force fended off repeated Japanese air attacks along the way and conducted strikes on Luzon on the October 15 and 16.

The "knock-down, drag-out fight between carrier-based air and shore-based air," as Halsey later described it, was a decisive American victory.

Air attacks by TF 38 and raids by B-29 bombers launched from US-held islands destroyed about 500 Japanese aircraft, sunk several supply freighters, and thoroughly wrecked many ammo dumps, hangars, airfields, barracks, and workshops on Formosa.

The US lost just 89 planes, with 64 pilots and crew members killed. Both damaged cruisers were towed to Ulithi, a major repair hub for the US Navy.

Japan's losses were so severe that they were unable to provide air cover for Japanese ships during the Battle of Leyte Gulf from October 23 to October 26.

In that clash, Japan lost four carriers, three battleships, 10 cruisers, and nearly a dozen destroyers. The battle also saw Japan's first major use of kamikaze pilots, reflecting its dwindling options and growing desperation.

The thrashing Japan suffered at Formosa was embarrassing, especially since there was still a belief at the time that ground-based aircraft would have an advantage over attacking carrier-based aircraft.

Publicly, Japanese leaders lied about the battle around Formosa, claiming their forces sank multiple US warships. Those claims were put to rest when Halsey and all the ships of Task Force 38 arrived in the Philippines on October 17.

In a dispatch to Adm. Chester Nimitz, who was commander of the US Pacific Fleet, Halsey said "the Third Fleet's sunken and damaged ships have been salvaged and are retiring at high speed toward the enemy" — a message that so pleased Nimitz that he had it broadcast to the public on October 19.