A Chinese blockade of Taiwan would be an act of war that sparks a global crisis. It would provoke a military response by Taiwan, force President Trump to decide whether the U.S. military should help defend the island, disrupt global trade and impel European nations to impose punishing sanctions on Beijing.
But the Chinese military, empowered by a decadeslong buildup and ordered by leader Xi Jinping to rapidly modernize by 2027, already has demonstrated what it can do. In increasingly complex exercises, Chinese forces have encircled Taiwan and simulated blockades.
The more that China prepares, the greater the risk that Beijing decides to shift without notice from drills to war. China claims Taiwan as its own territory and doesn’t rule out the use of force to seize it.
A blockade is one of Xi’s most powerful military options—short of an invasion, a steep challenge for the not-yet-battle-tested Chinese military—to induce the island to surrender to Beijing’s authority.
China’s military exercises provide clues about how Beijing would enforce a blockade. The Pentagon, military experts and monitoring by Taiwan fill out the picture of how it would take shape and the readiness of China’s armed forces to carry it out.
China has many options—recent tabletop wargames led by Taiwan’s president investigated around a dozen versions of a blockade or similar action, according to people who took part—but all share common features.
Here is how the U.S., Taiwan and independent experts suggest China’s forces—from navy to civilian maritime militia—could work together to isolate Taiwan.
China has displayed elements from the expanding arsenal of blockade tools at its disposal on a near-daily basis. A record 125 Chinese military aircraft, including jet fighters, helicopters and drones took part in large-scale air-and-sea drills in October that simulated a blockade of Taiwan, according to Taiwan’s defense ministry.
China’s military described the event as combat-readiness drills, including for sea and land strikes and port blockades. China’s defense ministry and its Taiwan Affairs Office didn’t respond to questions about Beijing’s plans.
China has sizable means of striking Taiwan available: Its air force operates around 1,900 jet fighters and 500 bombers, while its rocket force has more than 3,000 missiles capable of reaching Taiwan, according to the Pentagon. Taiwan’s Defense Ministry this week identified drone warfare in particular as an area of growing Chinese capacity and Taiwanese concern.
In blockade scenarios drawn up by the U.S., Taiwan and others, when China’s air assault begins, its navy—the world’s largest, with more than 370 vessels at its disposal—is already in motion.
The size of the fleet reflects a long growth spurt that hasn’t ended. China is the world’s top shipbuilder by a wide margin, and that includes warships for its growing navy. In 2000, the U.S. had more warships, but China surpassed the U.S. two decades later. China is projected to have 425 warships by 2030, outnumbering the U.S. fleet by more than one-third, according to the Congressional Research Service.
While China’s aircraft carriers are seen as less capable than their American counterparts, China is working to catch up. After adding its second carrier in 2019, China is expected to put a third into service this year. And in a fleet of 59 submarines, China’s six nuclear-powered ballistic-missile submarines are all assigned to commands that would participate in a direct conflict with Taiwan’s navy, according to the Pentagon.
China’s naval buildup also has enhanced its geographical reach. In December exercises, China deployed more than 90 naval ships and coast guard vessels accompanied by several thousand personnel, Taiwanese officials said. Vessels turned up around Taiwan, in the waters surrounding Japan and South Korea, and in the South China Sea.
China’s coast guard claimed in October for the first time to have fully encircled Taiwan—and marked the milestone by publishing a map that depicted its deployment in a heart-shaped formation around the island.
Cyberwarfare is another area in which China has rapidly developed a capability that would be put to work in the event of a blockade. Almost every large-scale Chinese military drill around Taiwan has been accompanied by a surge in cyberattacks, according to Taiwan authorities, and a blockade would be no different. And in several recent incidents, the cutting of subsea fiber optic cables has highlighted the vulnerability of Taiwan’s connection to the internet.
A vulnerable Taiwan
Taiwan relies on imports for 96% of its power, through foreign oil, coal and natural gas. A blockaded island would have to rely on stockpiled energy imports, submit to Beijing, or go dark. The island imports around 70% of its food supply, another security gap.
With a blockade, China could probe Taiwan’s defenses while trying to suffocate its economy and undermine its determination to resist.
Short of a blockade, Beijing has the ability to implement a quarantine, in which Chinese law-enforcement agencies intercept ships that deliver life-sustaining imports to the island, while causing less disruption to China’s own shipping lanes.
A quarantine would likely start with the announcement by Beijing of new rules requiring inspections for ships entering Taiwan—possibly targeting only the largest port, Kaohsiung.
While Beijing could use its vast number of vessels to enforce a quarantine, it holds another cudgel: Shipping companies that don’t comply could be barred from access to China.
To tighten the screws on Taipei, Beijing could move to block gas shipments that transit through the South China Sea, where China has exercised control over contested territory.
“I think there’s general agreement both in the United States and Taiwan that if China wanted, it could quarantine or blockade Taiwan today,” said Bonny Lin, a senior adviser at the Center for Strategic and International Studies.
Defending the island
Concerns about China turning drills around Taiwan into an actual attack have unnerved the island’s government and military officials. Taiwan’s military held a five-day drill ending Friday designed to immediately prepare for war, and a coming exercise will be based on the premise that China plans to invade in 2027—the year that Xi set as a goal for invasion readiness, in the view of some Western intelligence officials.
Most military experts agree that China’s armed forces aren’t ready for an amphibious invasion across the 110-mile-wide Taiwan Strait. The seas are often rough and Taiwan’s cliffs, mud flats and built-up coastlines make it hard for ships to land. Taiwan’s antiship missile systems, some of them acquired from the U.S., also represent a deterrent.
The U.S. president’s stance on Taiwan likely plays the most crucial role in Beijing’s calculation about whether to take action, said Huang Chung-ting, a Taipei-based defense analyst at the Institute for National Defense and Security Research, a think tank backed by the Taiwanese military.
The prospect of a U.S. military response remains a wild card. Trump’s commitment to defending the island is uncertain, and his recent suspension of U.S. support for Ukraine caused a rupture with Europe, diminishing the threat of unity on sanctions.
“Our worst nightmare scenario involving a blockade actually comes from American isolationism—where the U.S. decides to completely step away from Taiwan Strait issues,” said Huang.
In the short term, a quarantine would be more likely than a blockade or invasion, according to Lin and her CSIS colleagues. Such a step would test the will of the U.S. and others to respond, while potentially allowing China to establish a new normal at sea.
Write to Joyu Wang at joyu.wang@wsj.com and Austin Ramzy at austin.ramzy@wsj.com
