China’s unexplained 40-day reservation of a vast offshore airspace signals a significant shift in its military readiness, sparking concerns over regional stability.
China has reserved a swath of offshore airspace larger than Taiwan for 40 days without explanation, an unprecedented move that analysts say could signal a shift to a "sustained operational readiness posture" and heightens geopolitical risk in the Indo-Pacific. The alerts, formally known as “Notice to Air Missions” (Notams), are in effect from March 27 through May 6 and cover areas extending from the Yellow Sea facing South Korea, south to waters of the East China Sea facing Japan.
"What makes this especially notable is the combination of SFC-UNL with an extraordinary 40-day duration—and no announced exercise,” said Ray Powell, director of the SeaLight project at Stanford University, which tracks Chinese maritime activity. “That suggests not a discrete exercise but a sustained operational readiness posture—and one that China apparently doesn’t feel the need to explain.”
The reserved airspace has no vertical ceiling and follows a recent mysterious pause in China’s near-daily military flights near Taiwan. The developments come as U.S. attention is diverted by conflict in the Middle East and alongside Japan's deployment of long-range missiles capable of reaching China’s mainland.
The prolonged airspace reservation, far exceeding the typical 3-day warnings for military drills, could provide China’s military an opportunity to practice air combat maneuvers required in a potential conflict over Taiwan. This action, which a senior Taiwanese official described as "clearly aimed at Japan," could increase market volatility in Asian indices like the Nikkei and TAIEX and prompt a flight to safer assets like the U.S. dollar and gold.
While China has issued similar reserved-airspace Notams along the same stretch of coast at least four times in the past 18 months, those were for much shorter, typically 3-day blocks, according to Ben Lewis of the research organization PLATracker. The longer 40-day window likely means China’s military is “giving itself scheduling flexibility” for spring training, he said.
However, if the zones are confirmed to be linked to exercises, the warnings “would represent a meaningful shift in how Beijing uses airspace control as a tool of military signaling,” Powell said. The reserved airspace could “provide an opportunity to practice the kinds of air combat maneuvers that would be required in such a scenario,” said Christopher Sharman, director of the U.S. Naval War College’s China Maritime Studies Institute.
The move coincides with several politically significant events. The leader of Taiwan’s opposition Kuomintang party, which supports friendly ties with Beijing, is visiting China. This is in stark contrast to Taiwan’s ruling Democratic Progressive Party, which advocates for building up the island's defenses. A U.S. congressional delegation also recently visited Taiwan, Japan, and South Korea, urging Taipei to approve a large military budget for U.S. arms purchases.
Officials in Taiwan believe China is seizing an opportunity to increase its active military presence while U.S. attention is diverted. The reservation of zones is “clearly aimed at Japan,” as China looks to deter U.S. allies and erode American military influence in the Indo-Pacific region, a senior Taiwan security official said.
This article is for informational purposes only and does not constitute investment advice.
