Japan plans more bomb shelters for outlying islands amid ‘growing concern’ over Taiwan tensions

Tokyo is concerned, however, that a sudden outbreak of hostilities involving Taiwan and close to Japanese islands such as Yonaguni – which is only 111km from Taiwan – would not give the Japanese authorities time to conduct an evacuation, meaning that residents would be required to shelter in place.

NHK reported that government officials had been examining existing structures on the islands and had identified robust concrete buildings that could be modified to provide shelter. Such buildings would be retrofitted with concrete walls at least 30cm thick to withstand missile and bomb blasts, and be equipped with independent power sources, communications systems and storage for food and medical supplies.

The proposal calls for every person to have 2 square metres (21.5 square feet) of space and for the supplies to be sufficient to support evacuees for up to two weeks.

“The government’s priority is to try to evacuate people who are living on the most remote islands and finally to transport them to Kyushu,” Iida said.

“But they are also planning to build shelters for those who are not able to move immediately,” he added. “Evacuating an island like Yonaguni would be very challenging, so a more realistic approach is needed.”

Some analysts have suggested that if China wanted to invade Taiwan, it would have no choice but to attack US military bases in Okinawa to neutralise the threat to the northern flank of any invasion fleet. Any attack on US bases would also be an attack on sovereign Japanese territory, Iida said, and would require a response.

“We are not predicting that China will attack,” he said. “But we do have to be prepared for the worst-case scenario.”

Garren Mulloy, a professor of international relations at Daito Bunka University and a specialist in military issues, said greater military infrastructure on Japan’s outlying islands was a double-edged sword and had caused divisions among local communities.

“The Japanese government has been building a greater military footprint on many of these islands and the positive impact is that it gives Japan greater contingency capability for the national and local government in the event of a natural disaster, in addition to its defensive role, and it has brought more people to communities that are facing the problem of depopulation,” he said.

On the other hand, he said, Ground Self-Defence Force (GSDF) documents leaked in 2018 detailed scenarios for conflict in the region and suggested that if Chinese forces were to carry out amphibious assaults on outlying islands and captured them, then Japan would have no choice but to retake the territory.

The immediate reaction from the public was that a re-run of the bloody 1945 Battle of Okinawa would be inevitable, Mulloy said.

“Local people were not particularly opposed to the GSDF before that as they knew the bases brought benefits, from grants to an influx of young people,” Mulloy said. “But the conversation then changes to the bases making their islands a target, which set alarm bells ringing and divided local opinions.”

Nevertheless, the local government on Yonaguni was shocked at the scale and intensity of Chinese military activity when then US House Speaker Nancy Pelosi visited Taiwan in August 2022. A series of military exercises around the island included the launching of cruise missiles, with at least five weapons falling within Japan’s exclusive economic zone off Yonaguni.

Immediately after those drills, the town began surveying the limestone caves that dot the island and were used by previous generations to provide shelter when the US began its assault on Okinawa in 1945.