FILE PHOTO: A retired military tank is seen on the beach with China in the background in Kinmen, Taiwan December 20, 2023. REUTERS/Ann Wang/File Photo
FILE PHOTO: U.S. Defense Secretary Pete Hegseth speaks at the IISS Shangri-La Dialogue security summit in Singapore, May 31, 2025. REUTERS/Edgar Su/File Photo

By Greg Torode, Ben Blanchard and Yimou Lee

HONG KONG/TAIPEI (Reuters) -The exercise presented a fraught scenario: China's military had blockaded Taiwan by air and sea, and Southeast Asian countries were grappling with how to evacuate as many as 1 million of their nationals trapped on the besieged island.

Over two days in April at a Singapore hotel, some 40 participants and observers in the war game, including serving and retired Asia-Pacific officials and military officers, as well as security scholars, simulated their responses to the unfolding crisis, according to four people familiar with the discussions.

Hours ticked by as some players weighed unified action through the Association of Southeast Asian Nations, while others reached out to the mock U.S., Chinese and Japanese delegates to negotiate special air and sea corridors to extract foreign nationals. Eventually, the people said, a stark conclusion emerged: The Southeast Asian states needed a Singaporean airlift to have a chance of evacuating their people.

"Nothing was moving until the Singaporeans stepped in at the 11th hour," said one participant in the event at the Jen Singapore Tanglin hotel. "They had found a way of getting their own people out, and offered to get others out, too."

Reflecting its discreet and decades-old security presence inside Taiwan, where its forces train, Singapore was able to leverage access to airfields and aircraft, the person said. But the exercise ended before any detailed discussion of how Singapore had reached a deal with China to secure an evacuation route through the blockade, or how precisely it would work, three of the people told Reuters.

The previously unreported exercise comes amid an escalating battle between the U.S. and China for dominance in the Asia-Pacific region. It offers a rare window into contingency planning over Taiwan, which some Asian and Western military attaches and security analysts say is becoming increasingly necessary because an assault on the island by Beijing could draw in the U.S. and imperil other countries.

While the scenario didn't reflect official policies, participants playing the roles of foreign and defence ministers worked from the known positions of at least nine governments depicted in the simulation, said the four people, who like some others spoke on the condition of anonymity to discuss a sensitive matter. Besides Singapore, China, Taiwan and the U.S., the rest included Indonesia, Vietnam and the Philippines, they said.

Southeast Asians account for about 94% of the almost 1 million foreign nationals resident in Taiwan, according to Taiwan's National Immigration Agency. Indonesians, Vietnamese and Filipinos make up the vast majority of those foreigners, with comparatively small numbers of Japanese and Americans.

Singapore's defence ministry said it wasn't involved in the "workshop" and none of its officials attended in any capacity. Neither the defence nor foreign ministries addressed Reuters questions about Singapore's military presence in Taiwan and planning for Taiwan conflict scenarios, including evacuations.

China's foreign ministry said it had "always resolutely opposed countries with whom it has diplomatic relations having any form of official relations with the Taiwan region, including military dialogue and cooperation," adding that it wasn't aware of the circumstances of the exercise.

The London-based International Institute for Strategic Studies (IISS), which organised the exercise, told Reuters in a statement that participants had attended in their private capacities, and that it could not comment on "discussions, attendees, or any other elements."

Taiwan's defence ministry and the ASEAN Secretariat in Jakarta didn't respond to questions.

A Pentagon official said they were not aware of any official participation in the event by the U.S. Defense Department. "We routinely engage with allies and partners to ensure readiness for a range of contingencies, but it would be inappropriate to discuss operational planning or hypothetical evacuation scenarios," the official said.

Weeks after the exercise, U.S. Defense Secretary Pete Hegseth told a security conference in Singapore that the threat of China using force to take Taiwan was "imminent" amid intensifying air and naval operations around the island by the Chinese military, the People's Liberation Army.

Chinese officials have said Hegseth and other Trump administration officials are playing up "the so-called China threat", with the Chinese embassy in Singapore saying his speech was "steeped in provocations and instigation".

China claims Taiwan as its territory and has never renounced the use of force to seize it. Taiwan's President Lai Ching-te and his government strongly object to China's sovereignty claims, saying it is up to the island's people to decide their future.

Drew Thompson, a Singapore-based security scholar, said it was vital for Southeast Asian countries to move beyond war games and contingency discussions to build meaningful, unofficial ties with Taiwan, particularly its military. These countries have diplomatic ties with Beijing and don't officially recognise Taipei.

"The big takeaway here is that a plan is one thing but you need the access and the relationships to put it into play," said Thompson, of the S. Rajaratnam School of International Studies, who wasn't involved in the exercise.

"Singapore has long had these ties, the Philippines is building them, but it remains an open question whether the other countries in Southeast Asia have the unofficial networks in place to meaningfully engage with Taiwan in a conflict."

The Philippines foreign ministry told Reuters the government has contingency plans for a Taiwan emergency, without offering specifics. It added that Manila has "legitimate interest in Taiwan due to geographic proximity and the presence of Filipino nationals there".

The foreign ministries of Indonesia and Vietnam didn't respond to requests for comment. Japan's defence ministry declined to comment.

'USEFUL PERCH'

Given recent drills in which Chinese vessels encircled Taiwan, some military attaches and analysts say any attempt by Beijing to seize the island could start with a blockade, which would be considered an act of war under international law.

The risks are felt acutely in Singapore, a financial and shipping hub that hosts U.S. Navy ships and surveillance aircraft yet maintains strong cultural, diplomatic and economic ties with China.

Singaporean forces have conducted military training in Taiwan since 1975, under an arrangement known as Project Starlight. The presence is seldom publicly acknowledged by officials in Singapore, which does not have formal diplomatic relations with Taiwan. But it remains important to Singapore's defence forces, according to seven diplomats and security scholars familiar with the matter.

Singapore rotates up to 3,000 infantry troops and commandos annually through three training camps in southern Taiwan, according to five of the seven people, where the mountains and jungles replicate conditions found on the Malay Peninsula.

"It gives Singapore a useful perch from which to watch both the Taiwan Strait and the top part of the South China Sea," said one Western security official.

China has long objected to the arrangement. But Singapore has held fast, in part because a withdrawal would represent a change to the delicate strategic and diplomatic balance around Taiwan, three of the scholars told Reuters.

Singapore's forces also train regularly in Australia, France, Brunei and the U.S. The city-state has the best-equipped military in Southeast Asia, according to an annual survey of the world's armed forces produced by the IISS.

Yet an outbreak of war in Taiwan could trap Singapore's forces there or render them bargaining chips that could give China military and diplomatic leverage over Singapore, according to some analysts and military attaches.

In a conflict, Southeast Asian governments would face an arduous task in evacuating their nationals from Taiwan, Ngeow Chow Bing, a Malaysia-based security scholar, wrote in a study published last year by the Carnegie Endowment for International Peace.

But, Ngeow wrote, Beijing has clear incentives to ensure that most, if not all, ASEAN members remain neutral.

"If Beijing cares how it is perceived in Southeast Asia during a Taiwan crisis, it follows that Beijing would view the evacuation of Southeast Asian citizens as crucial for its own diplomatic posture," he added.

(Reporting by Greg Torode in Hong Kong and Ben Blanchard and Yimou Lee in Taipei. Additional reporting by Singapore bureau, Laurie Chen in Beijing, Phil Stewart in Washington, Mikhail Flores in Manila, Faith Hung in Taipei, Khanh Vu in Hanoi, Tim Kelly in Tokyo and Ananda Teresia in Jakarta. Editing by David Crawshaw.)