TAIPEI, Taiwan — China’s People’s Liberation Army encircled Taiwan with 71 warplanes, two carrier strike groups and an estimated 27 surface combatants Wednesday in the largest single-day exercise around the island in two years, a show of force that Pacific defense officials read as a deliberate test of whether Washington and its regional allies could still mount a coordinated response while their senior diplomatic ranks remained absorbed by the Marseille reconstruction conference and the unfinished business of the Iran war.

The drills, designated “Joint Sword-2026B” by China’s Eastern Theater Command, were announced shortly before dawn local time and ran across three exclusion zones north, southwest and east of Taiwan. Taiwan’s Ministry of National Defense said 49 of the 71 aircraft crossed the median line of the Taiwan Strait, the de facto boundary Beijing has progressively erased over the past three years, and that the Shandong and the recently commissioned Fujian operated for the first time as a coordinated two-carrier formation east of the island.

President Lai Ching-te convened the National Security Council at the Presidential Office shortly after 8 a.m. and ordered Taiwan’s armed forces to a heightened alert posture short of full mobilization. In a four-minute statement read by spokesperson Karen Kuo, Mr. Lai called the exercises “a provocation without legitimate purpose” and said Taipei would “neither escalate nor flinch.”

“The Republic of China’s armed forces are watching every aircraft, every vessel, every signal,” Ms. Kuo told reporters. “We are not surprised, and we are not unprepared.”

The timing drew immediate notice in regional capitals. Wednesday opened the second and final day of the Marseille donor conference for Iran, Iraq and Yemen reconstruction, where French President Emmanuel Macron and Japanese Prime Minister Fumio Kishida were co-chairing pledging sessions and where U.S. Deputy Secretary of State Martin Voorhees was leading the American delegation in the absence of Secretary Marco Rubio, who returned to Washington late Tuesday for congressional testimony on the war supplemental. Senior Pentagon planners told reporters at a hastily arranged briefing in Honolulu that the exercise window had been selected with “obvious awareness” of the diplomatic calendar.

“This is the first significant Strait operation since the ceasefire took hold in the Gulf, and the message embedded in the timing is hard to miss,” said Adm. Stephen Koehler, the head of U.S. Indo-Pacific Command, in a televised statement from Camp H.M. Smith. He said two U.S. carrier strike groups, the George Washington and the Carl Vinson, were operating in the Philippine Sea and the South China Sea respectively, and that B-1B bombers from Andersen Air Force Base in Guam had been put on a higher readiness cycle. “We are postured. We are watching. We are not surprised either.”

Japan, which has spent much of April recalibrating its energy security architecture around Australian and American supply, scrambled F-15 and F-2 fighters from Naha Air Base on Okinawa as PLA aircraft transited the Miyako Strait. Defense Minister Gen Nakatani held a 25-minute call with U.S. Defense Secretary Pete Hegseth and a separate call with South Korean Defense Minister Shin Won-sik, the third such trilateral consultation in six weeks. “The lessons of the spring apply here, too,” Mr. Nakatani told reporters in Tokyo. “Energy lines, sea lines, communications lines — they are one set of vulnerabilities, and they require one posture.”

Beijing’s framing was, by contrast, tightly disciplined. Chinese Foreign Ministry spokesperson Mao Ning, in a brief afternoon briefing in Beijing, described the drills as “a stern warning against separatist forces” and rejected what she called “the habit of certain countries to read every Chinese military activity as a message to themselves.” The Eastern Theater Command spokesman, Senior Col. Li Xi, said the exercise would test “joint blockade, joint strike and joint seizure of comprehensive battlefield superiority” and would conclude when objectives had been met, without specifying a date.

Three regional analysts, speaking separately, said the operational tempo and integration of the two carriers represented a measurable step beyond last year’s Joint Sword-2025 series. “What is new is not the perimeter, it is the orchestration,” said Yuki Tatsumi, a Tokyo-based senior fellow at the Indo-Pacific Strategic Forum. “Two carrier groups, coast guard cutters operating inside Taiwan’s contiguous zone, drone swarms in the east — that is a rehearsal of a system, not a signaling exercise.”

Layla Hassan, a Beirut-based regional analyst who has spent the past month tracking how the postwar Gulf order has reshaped Asian strategy, said Beijing was probably reading the Marseille conference as evidence that European and American attention would remain tilted westward for months to come. “If you are looking for the window when Washington’s bandwidth is most divided, this is plausibly it,” she said. “China does not need to invade anything to make a point. It just needs to demonstrate that it can hold the ring while the rest of the system is looking elsewhere.”

In Manila, the Philippines’ Department of National Defense said it had repositioned two of its newly delivered BrahMos coastal missile batteries on Luzon and dispatched two Jose Rizal-class frigates to the Bashi Channel as a precaution. President Ferdinand Marcos Jr., on the second day of a state visit to Hanoi, called the exercise “an unwelcome reminder that the South China Sea and the Taiwan Strait are not separate theaters.”

Markets across the region absorbed the news with relative composure after an early wobble. The Taiex closed down 1.7%, the Nikkei 225 slipped 0.6% and the dollar gained against the New Taiwan dollar and the yuan in offshore trade. Shipping insurers said war-risk premiums on Strait crossings, which had drifted lower since the Iran ceasefire, would likely tick higher again pending the exercise’s duration.

Adm. Koehler said additional U.S. force-posture adjustments would be announced “as the exercise unfolds,” and the Taiwanese Defense Ministry said it would issue further situational updates at 6 a.m. local time Thursday.