China Is Running Out of Lines to Cross in the Taiwan Strait

In 2020, the balance of military power in the Taiwan Strait began a gradual but profound shift in China’s favor.

That August, then-Secretary of Health and Human Services Alex Azar became the highest-ranking U.S. cabinet official to visit Taiwan in more than four decades. Though he was there to talk about the pandemic, China’s People’s Liberation Army (P.L.A.) responded by carrying out large-scale military exercises around the self-governing island, sending aircraft over the median line of the Taiwan Strait for only the third time in more than 20 years. Since then, China has responded to such visits and other perceived provocations by flying more than 4,800 sorties, with growing numbers of aircraft flying in locations previously seen as off-limits and conducting dozens of increasingly complex air and naval military exercises around Taiwan.

The P.L.A.’s now-normalized presence around Taiwan raises the risk of an accidental confrontation. But over the longer term, it has also gradually created a dangerous sense of complacency in Taipei and Washington, while giving China the crucial operational practice it might one day need to seize the island.

As a military analyst specializing in China and Taiwan who has spent the last two years managing an open-source database tracking Chinese military activity, I am deeply concerned about the dangers that this activity poses. Alarm bells should be ringing, but neither Taiwan nor the United States have taken meaningful action to deter China, and Taiwan’s response has been inconsistent and lacks transparency, which may further embolden Beijing. A more robust approach is needed to deter China from escalating the situation.

In 2020, shortly after China began raising the pressure, Taiwan’s Ministry of National Defense started releasing daily reports on Chinese military activity inside the island’s Air Defense Identification Zone, a perimeter extending beyond Taiwan’s territorial waters and airspace that is monitored to provide early warning of approaching Chinese planes or missiles. In previous years, China rarely entered the zone. But in 2020, P.L.A. aircraft breached it nearly 400 times. Last year, that number exceeded 1,700.

Beijing has steadily pushed the envelope. P.L.A. forces also rarely crossed the median line of the Taiwan Strait, the halfway point between China and Taiwan. But in August 2022, after a visit to Taiwan by Nancy Pelosi, then the speaker of the U.S. House of Representatives, Chinese forces crossed the line 302 times that month, essentially erasing it as a functional boundary. Today, Chinese aircraft continue to cross the line almost daily, leaving Taiwan only minutes to assess China’s intentions in a dangerous guessing game that leaves the door open for miscalculation. Since last year, China also has essentially established a permanent naval presence around the island.