BRIEF: China's NOTAMs and Taiwan

CHINA: Airspace restrictions over the East China Sea likely indicate an unannounced military exercise of unprecedented size.

As of 5 April 2026, China’s People's Liberation Army Air Force (PLAAF) has issued an unusually long¹ Notice to Air Mission (NOTAM)² restricting air travel over the Yellow Sea and East China Sea for the next forty days. This notice represents a significant escalation in China airspace restrictions, which generally last for no more than three days³. No military exercises have been declared for the NOTAM period, but major military exercises are likely to occur in the restricted zone.

Military exercises in this restricted zone would very likely include intelligence-collection regarding Japanese capabilities; China’s January 2026 blockade drills near Taiwan included drone reconnaissance over Taipei.⁴ The restricted areas are located near the western coast of Japan⁵, where Liberal Democratic Party hardliner Sanae Takaichi has recently taken a firm anti-China stance⁶. In October 2025 Takaichi said Japan would defend Taiwan militarily in case of a Chinese invasion⁷. Under her tenure, the Japan Self-Defense Forces (JSDF) has developed and fielded its first long-range hypersonic missile⁸, the Type 25. On 1 April 2026, the JSDF announced the deployment of the Type 25⁹ at a base on the East China Sea. Chinese state media slammed the weapon¹⁰ as a violation of the non-aggression clause of Japan’s post-WWII constitution.

Military exercises in the restricted zone also likely aim to intimidate Taiwanese political and military leadership. The Taiwanese opposition party, the Kuomintang (KMT) is scheduled to visit China next week, and the party chair will likely meet with president of China Xi Jinping¹¹. This would represent a major acceleration in the diplomatic process between China and Taiwan.

A continuous multi-week military exercise cannot be ruled out; Chinese military exercises have radically increased in size since 2022, and show no signs of stopping. A fresh round of drills would raise tensions in East Asia as Xi Jinping continues to express his intent to “re-unify” China and Taiwan by 2027.

Combined operational zones of PLA drills, 2022-2026.

1. https://www.taipeitimes.com/News/taiwan/archives/2026/04/07/2003855165

2. https://www.taipeitimes.com/News/taiwan/archives/2026/04/06/2003855129

3. https://www.wsj.com/world/china/china-creates-new-aviation-mystery-with-offshore-warning-zones-128b1ce5?gaa_at=eafs&gaa_n=AWEtsqdRSDlcftF7Q2UZn0M-vZTMC2vdQhyzutywA1qPo1ssHSrO4CMPm5P7zuR8Elo%3D&gaa_ts=69d55f46&gaa_sig=JoQfn6of18etnW0jqJFp10YW_4SV1NJTuEDacspfpXGEDg8uolqxrKqreAfle50KpsDuXKFSviavIzLR2q21zg%3D%3D

4. https://understandingwar.org/research/china-taiwan/china-taiwan-update-january-23-2026/

5. https://www.taipeitimes.com/News/taiwan/archives/2026/04/06/2003855129

6. https://www.bbc.com/news/articles/c86y3ndqlxwo

7. https://www.reuters.com/world/china/why-did-japan-pms-taiwan-remarks-cause-such-stir-2025-11-11/

8. https://www.navalnews.com/naval-news/2026/03/japan-deploys-new-longer-range-missiles-formally-designates-type-25-systems/

9. https://news.usni.org/2026/04/01/japan-deploys-new-hypersonic-anti-ship-missiles

10. https://apnews.com/article/japan-china-taiwan-missile-longrange-40322ab51735b2ce17ce6f02d224d14f

11. https://www.reuters.com/world/china/world-does-not-need-crisis-over-taiwan-opposition-leader-says-ahead-china-trip-2026-04-01/