The US aborted the invasion of Taiwan in World War II; Move offers lessons for China today

• The US considered invading Japanese-occupied Taiwan during World War II.
• Top American commanders decided it would be a nightmare with many casualties.
• Chinese invaders could face similar challenges today.

The US once planned an invasion and conquest of Taiwan that would have been this big D-day.

Operation Causeway would send hundreds of thousands of troops, supported by thousands of ships and aircraft, to storm the beaches of the Japanese-occupied territory in 1945.

“Almost certainly the invasion would have been a gruesome spectacle and a nightmarish ordeal,” said Ian Easton, an analyst who wrote a new paper. study on the invasion for the China Maritime Studies Institute. “Far worse than any battle actually fought in the Pacific. The campaign would have been protracted, perhaps lasting six months or even a year.”

The CMSI study makes clear that a US invasion of Taiwan in 1945 – or a Chinese invasion today – would be difficult and risky.

Like many years ago, today’s Taiwan would likely employ Japanese fortifications and tactics to defeat a major Chinese amphibious assault – illustrating the risks and dangers of any attempt to conquer the island held by Beijing. viewed as a separate province.

‘A long and drawn out fight’

The genesis of the planned U.S. invasion—eventually codenamed Operation Causeway—began in the late 1920s as the U.S. Navy and Army developed a strategy for a possible war with Japan. The Orange War Plan envisaged an advance across the Pacific Ocean that would culminate in an attack on Taiwan – then still called Formosa – which the Japanese Empire would annexed from China in 1895 after the First Sino-Japanese War. The plan called for 90,000 army and navy personnel to conquer Taiwan, making the island a staging post for an invasion of Japan. In the 1930s, Taiwan was rejected in favor of conquering Okinawa, a smaller objective closer to Japan’s four largest islands.

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In 1944, as Japan crumbled and an invasion of the Japanese mainland seemed likely, American planners again looked to Taiwan as an amphibious staging post and a base for strategic B-29 Superfortress bombers. Navy Chief Adm. Ernest King favored the Taiwan option, while General Douglas MacArthur lobbied for an invasion of the Philippines. For a time, “General MacArthur’s return to the Philippines was viewed as a secondary and supporting campaign,” the CMSI investigation said.

Initial plans called for an attack by twelve divisions in early 1945. But as the European theater took priority for American forces, this was reduced to six divisions (approximately the size of the initial assault force during the Normandy invasion). The aim would be to occupy southern Taiwan and the Chinese port city of Xiamen across the Taiwan Strait.

But this meant subduing a heavily defended island of 22,000 square kilometers dotted with towns, mountains and forests. The more they studied the challenges, the more worried some senior officers became. Just finding enough forces would be a nightmare. “In total, it was estimated that a force of 776,913 would be required for Causeway, including all six divisions of the US Marine Corps, 20 B-29 bomber groups, 41 assorted bomber squadrons, 40 fighter squadrons and large numbers of naval engineers and logistics support units” , the CMSI report said.

The biggest mistake in Operation Causeway was an underestimation of the Japanese defenses. Intelligence assessments expected a garrison of 90,000 to 170,000 troops. In fact, the Japanese had 275,000 troops, inclusive conscripted Taiwanese natives. They were supported by 20 squadrons of kamikaze aircraft and 600 suicide boats.

The Japanese had expected the landings to take place in southern Taiwan. They planted 10,000 naval mines, 5,200 of them in the Taiwan Strait alone. Aware of overwhelming American firepower, they built extensive systems of trenches, bunkers and tunnels over the beaches and throughout the island.

“Imperial Japanese and Formosan forces would have fought a long, drawn-out battle in the cities and the mountains,” Easton said. “A guerrilla warfare campaign was planned after conventional fighting came to an end. Taiwan’s defenders were determined to fight to the bitter end, and the defensive geography, supplies and underground bunkers they had were extraordinary.”

How would a US invasion of Taiwan proceed? Other battles in the Pacific War offer grim clues. When American troops landed in the Philippines in October 1944, they trudged through jungles and mountains in a campaign that had still not ended when Japan surrendered in August 1945. invasion On Okinawa Island, U.S. forces suffered 50,000 casualties in two months as they faced dense fortifications in hilly terrain and 2,000 kamikaze aircraft that sank or damaged hundreds of Navy ships.

Ultimately, the Taiwanese idea was abandoned. “From a military point of view, this was absolutely the right decision,” Easton said. “Professional war planners abhorred the idea of ​​fighting on Taiwan, and for good reason.”

Lessons for China

Even eighty years after the end of the Japanese occupation, Taiwan’s military is still influenced by Japanese doctrine, such as the importance of hardening air bases and how to confront an amphibious invader armed with massive air and naval firepower.

Taiwanese forces still use Japanese-built facilities, including some bunker complexes. Some Taiwanese officers advocate renovating old beach defenses and preparing for a prolonged guerrilla war, as the Japanese did.

China would face these and many more challenges if it tries to conquer Taiwan today.

“Taiwanese military officers pay close attention to history, especially the history of island warfare, urban warfare and amphibious warfare,” Easton said. “They have all the defensive advantages that the Imperial Japanese enjoyed and more, thanks to modern weapons and strong American support.”

Michael Peck is a defense writer whose work has appeared in Forbes, Defense News, Foreign Policy magazine and other publications. He has an MA in Political Science from Rutgers Univ. Follow him further Tweet And LinkedIn.