TAIPEI, Taiwan--If the United States gets embroiled in a war with China, it may begin with the lights going out here in Taipei.

Tensions are rising across the Taiwan Strait, and there’s a growing concern among some security experts that Chinese President Xi Jinping might act recklessly toward Taiwan in the next few years, drawing the United States into a conflict.

Xi’s hard line toward Hong Kong is alarming Taiwanese and further reducing the chance, if there ever was any, of a peaceful unification of China. China seems to be abandoning its effort to win hearts and minds on Taiwan, and it has steadily improved military capabilities--thus prompting the fear that Xi might eventually use them.

“We are very concerned,” Taiwan’s foreign minister, Joseph Wu, told me. He said that one concern was that a slowing economy and other troubles in China might lead Xi to make trouble for Taiwan as a distraction. “This is the scenario that is constantly playing in the minds of the key decision-makers” on Taiwan, he said.

The main worry of military planners here isn’t so much a full-scale amphibious invasion. Rather, they fear the mainland sowing chaos and disrupting the economy as a way of trying to bring Taiwan to heel.

Hence the concern about a cyberattack that would take out Taipei’s electric grid. Or sabotage of the underwater cables that bring data and internet to Taiwan. Or interference in the South China Sea with tankers carrying oil to Taiwan.

Wu added that China could also step up military pressure by increasing patrols in the area, or by holding military exercises. Even a partial blockade would have a substantial impact if it raised insurance costs and damaged confidence in the island’s future.

Government officials in Taiwan were cagey about how they would respond to provocations in cyber and other realms, but Wu said that military officials “are planning for defense and offense.” Another senior government official said that retaliation could include airstrikes on China’s Fujian province.

That fits with the belief that Taiwan would promptly escalate to bring the war to China. If that happens, no one knows quite what the U.S. would do, including the U.S. itself. A 1979 American law suggests that the United States is committed to Taiwan’s defense, but the law is ambiguous about just how committed.

China has been vastly improving its military capabilities, including its ability to strike aircraft carriers. I’m told that in 18 of the last 18 Pentagon war games involving China in the Taiwan Strait, the U.S. lost. Still, that can be misleading, because the war games are much more limited than real life would be. For example, the United States could interrupt China’s oil supplies from the gulf.

Beijing has also been nibbling away at Taiwan’s international presence, blocking it from participating in the World Health Organization and other United Nations agencies, and even barring Taiwanese from taking tours of the U.N. and Taiwanese journalists from getting U.N. accreditation.

President Donald Trump has generally been more supportive of Taiwan than his predecessors, and that’s worked well so far. But this has to be done very carefully. While Taiwan and China may know each other’s red lines, I worry that American politicians may try to help Taiwan in ways that increase the risk of triggering a crisis. Nothing can be so dangerous as a well-meaning American.

Aside from its efforts to isolate Taiwan, China also appears to be borrowing from the Russian playbook and using Facebook and other platforms to interfere with Taiwan’s democracy in the run-up to crucial elections in January.

“China is trying to discredit and dismantle Taiwan democracy,” said Ketty Chen of the Taiwan Foundation for Democracy.

A war between the United States and China over Taiwan would be a cataclysm. But it would also be a catastrophe if Taiwan were blockaded or squashed into submission, because it is a pillar of technology (the source of more than 90 percent of the most advanced computer chips), a pillar of democracy and an “unsinkable aircraft carrier” standing in the way of any Chinese projection into the Pacific or toward, say, Okinawa.

There are steps the U.S. can take that might reduce the risk of a crisis. Washington can emphasize to Beijing that Taiwan will not take any unilateral action, such as declaring itself an independent country--unless China makes a military move, in which case it will do so at once. The U.S. can also caution Beijing that if the electricity goes out in Taipei, the same may happen in Shanghai, and that if Taiwan-bound ships are harassed, they may be reflagged as American vessels.

But that means thinking through what might happen in the next few years and making clear to Xi that he will pay an extremely high price if he messes with Taiwan’s freedom.

(Sept. 4, 2019)