TAIPEI • On a cloudy day last month, thousands of soldiers massed on a beach in central Taiwan for the culmination of five days of exercises intended to demonstrate how the island's military would repel an invasion from China.
Jets, helicopters and artillery and missile batteries fired live ammunition at targets offshore, sending plumes of sea spray into the air. Then, a few hours later, a military helicopter taking part in the same exercise crashed at an airfield farther up the coast, killing two pilots and casting a shadow over the show of force.
It was the latest in a string of deadly mishaps, including a crash in January that killed the military's top commander, which have given new urgency to the debate over Taiwan's readiness to defend its 24 million people - with or without the help of the United States.
"I have to be honest: Taiwan's military needs to improve a lot," Mr Wang Ting-yu, a member of the Parliament's foreign affairs and defence committee, said in a telephone interview.
Taiwan's leaders have been moving to shake up the military and increase spending. Military tensions across the Taiwan Strait have surged in recent months as Taiwan has increasingly become a focal point in the confrontation between China and the United States.
Last week, the People's Liberation Army of China held a fresh round of live-fire exercises - an unusually concentrated training schedule that the state news media said was directed at Taiwan and the US.
The latest involved a test firing of four medium-range ballistic missiles into an area of the South China Sea near Hainan last Wednesday. The barrage came a day after China accused the Americans of flying a spy plane over one of the exercises, calling it a "naked provocation".
China has long threatened to use force, if needed, to prevent any movement towards formal independence for Taiwan, a self-governing democracy.
China has stepped up those warnings ever since Taiwan's President, Ms Tsai Ing-wen, won re-election in January by vowing to protect the island's sovereignty.
That has raised fears that Chinese President Xi Jinping could feel compelled to act aggressively, as China has in areas from the South China Sea to the border with India.
Chinese aircraft and warships have repeatedly menaced Taiwan's airspace and territorial waters in recent months, while officials have taunted its military, comparing it to "an ant trying to shake a tree".
"The likelihood of a military clash is much higher than before," said Mr Lin Yu-fang, a Taiwanese former legislator from the Kuomintang, the opposition party that ruled the island for decades.
Ms Tsai has responded to China's muscle flexing by pressing ahead with military changes. She has moved to revamp Taiwan's military doctrine and strengthen its reserves, a force that would be crucial to defending the island in the event of an invasion.
Ms Tsai's government announced this month that it would increase Taiwan's defence budget by 10 per cent, on top of a 5 per cent increase the year before. That would raise military spending to more than 2 per cent of gross domestic product.
Taiwan also finalised a deal announced last year to buy 66 American F-16 fighter jets, worth US$62 billion (S$84.2 billion), over the next 10 years.
By law, the US is committed to providing Taiwan with the support necessary to defend itself, a point reiterated by US Secretary of Defence Mark Esper in a recent talk. Yet it is far from clear whether the US would risk a broader confrontation with a nuclear-armed China, meaning Taiwan cannot count on it as a matter of strategy.
Ms Tsai's predecessor Ma Ying-jeou has accused her of clinging to hopes that as long as Taiwan puts up an initial defence, the US would intervene on the island's behalf, a scenario he considered impossible.
Mr Ma did not elaborate, but Ms Tsai said in an interview last year that Taiwan would be able to hold out for 24 hours and then China would face international pressure.
For decades, Taiwan's security was assured by the island's military capabilities, but China's efforts to modernise its forces have upended the balance of power.
China now has "an array of options for a Taiwan campaign, ranging from an air and maritime blockade to a full-scale amphibious invasion", according to a 2019 Pentagon report on the Chinese military.
The report acknowledged the challenges the Chinese army would face in such an attack, but said China's build-up "has eroded or negated" many of Taiwan's advantages. Those include the island's geography and the technical superiority it once had from buying American and other foreign weaponry.