The democratic island of Taiwan is making preparations for war, in response to China’s ratcheting up of military tensions with repeated incursions by air and sea, ministers said on Wednesday.

Taiwanese defense minister Chiu Kuo-cheng said China's People's Liberation Army (PLA) destroyed what he called a "tacit agreement" when it made incursions across the median line of the Taiwan Strait, which separates the island from China.

Chiu told lawmakers in Taipei on Wednesday that Taiwanese forces would react if China crossed a "red line," although he didn't specify what such a red line might be.

Chinese military aircraft have repeatedly crossed the median line since an Aug. 2 visit to Taiwan by U.S. House Speaker Nancy Pelosi riled Beijing.

Taiwan has never been ruled by the Chinese Communist Party (CCP), nor formed part of the People's Republic of China, but Beijing insists it has a territorial claim on the island, which was a Japanese dependency for the first half of the 20th century.

"The median line was supposed to be a tacit agreement for everyone," Chiu told a Legislative Yuan committee. "That tacit agreement has been destroyed."

The median line, which lies around 40 k.m. (25 miles) from Taiwan's waters, was delineated by a U.S. general at the height of hostility between Beijing and Taipei in 1954, and the PLA largely respected it until a foreign ministry spokesman said there was no such thing in 2020.

"They want to build a new normal but we do not change ... We will stand firm when they come. We do not give in," Chiu said.

'Irresponsible actions'

Taiwan president Tsai Ing-wen has repeatedly rejected Beijing's insistence on "unification," saying the island's 23 million people have no wish to give up their sovereignty or democratic way of life, a view largely backed up by recent opinion polls.

Tsai condemned Chinese military moves in an online think tank event Tuesday, where she expressed gratitude for support from the U.S., G7 countries and called for solidarity in the face of Beijing's threats.

"These irresponsible actions encroach on Taiwan's sovereignty and threaten peace and stability in the Indo-Pacific region. They also endanger air and maritime safety as well as international trade in an attempt to erode international law and norms," Tsai told an event shown by the Global Taiwan Institute, a Washington think tank.

"We know from history and current events that threats against any one country or region translate, directly and indirectly, to increasing threats against its neighbors. This is why global solidarity is key to countering authoritarian expansion, safeguarding democracy, and addressing shared challenges," she said.

Chiu said Taiwan is already preparing for a Chinese invasion.

"We are building up our arsenal and preparing for war according to our own plan," he told lawmakers.

Meanwhile, deputy economy minister Chen Chern-chyi told journalists that the government is already taking monthly inventories of critical food and energy supplies.

State-run Taipower and state-owned refiner CPC Corp are already primed to ensure energy supplies, Chen said.

"We want to ensure we have a certain period of stockpiles in Taiwan, including food, including critical supplies, minerals, chemicals and energy of course," he said.

According to a recent article by former CIA analyst John Culver, China could invade as early as 2024, but some estimates say 2027 is more likely.

But there will be sure signs that war is coming, Culver wrote in an op-ed for the Carnegie Endowment for International Peace, citing halted demobilization and regular drills, the building of field hospitals and propaganda exercises aimed at preparing the general population for the impact of military conflict.

"If China decides to fight a war of choice over Taiwan, strategic surprise would be a casualty of the sheer scale of the undertaking," Culver wrote. "Even if Xi were tempted to launch a quick campaign and hope that Taiwan’s will to fight would quickly collapse, Russia’s disastrous invasion of Ukraine probably has induced more caution in Beijing."

"Any invasion of Taiwan will not be secret for months prior to Beijing’s initiation of hostilities. It would be a national, all-of-regime undertaking for a war potentially lasting years," he said.

Chao Chun-shan, a China expert at Taiwan's Tamkang University, said the invasion is almost certainly on the CCP's agenda.

"They have already put this on the agenda for sure," Chao told RFA. "[We just don't know] whether it'll be in the short, medium or long term."

PLA capabilities in question

But he agreed that there are question marks over the PLA's capabilities to stage a massive amphibious invasion.

"Many people say that the CCP, especially the navy, is a match for the United States, but I think the CCP's military strength is still far behind that of the U.S," Chao said.

"After 2027, the likelihood they will fight this war is higher."

Lin Po-chou, Chinese military expert at Taiwan's Institute for National Defense and Security Research, said it is still unclear exactly how much military support the U.S. would offer Taiwan in the event of a Chinese invasion.

"If it's going to be an allied operation, there will need to be a lot of coordination and drills beforehand," Lin told RFA.

"A while ago, there were reports that the U.S. was planning to stockpile weapons in Taiwan. So the form this so-called aid will take is still unclear."

CIA chief Bill Burns told CBS News on Oct. 3 that developments in Ukraine may have changed CCP leader Xi Jinping's approach to Taiwan.

"I think President Xi is watching what's happening in Ukraine like a hawk," he told the network. "I think he's been sobered to some extent by the poor performance of the Russian military."

"That Chinese leadership is also looking at what happens when you stage an invasion, and the people you're invading resist with a lot of courage and tenacity as well." (KB/RFA)