China has lodged a “serious diplomatic” protest with Japan over its latest defence white paper, which portrayed Beijing as Tokyo’s “greatest strategic challenge” and made “brazen comments” on Taiwan, further escalating tensions between the two countries.

“The white paper once again targeted China with groundless accusations, rehashing the so-called ‘China threat’ and grossly interfering in China’s internal affairs with brazen comments on China’s Taiwan region,” Foreign Ministry spokesperson Lin Jing said on Wednesday (August 5, 2026).

“We deplore and firmly reject this, and have lodged serious representations with Japan,” he said while answering questions over Japan’s new defence white paper.

Defending recurring military drills around Taiwan, which China claims as part of its territory, Mr. Lin said, “Taiwan is an inalienable part of China’s territory. The Taiwan question is entirely China’s internal affair. How to resolve it is a matter for the Chinese ourselves and Japan is in no place to interfere.”

About disputed islands in the East China Sea, he said, “Diaoyu Dao and its affiliated islands have been China’s territory since ancient times.”

The islands, called Senkaku by Japan and Diaoyu Dao by China, are controlled by Tokyo. The Chinese coast guard periodically conducts patrols around them to assert Beijing’s sovereignty.

The white paper approved by Japan’s cabinet on Tuesday (August 4) said China’s growing military actions are Japan’s top security challenge and “must be addressed through overall national strength and cooperation with allies and like-minded nations.”

The nearly 600-page white paper contained a detailed assessment of the increasingly volatile regional security environment.

Coinciding with the release of the white paper, Japan showcased its new anti-ship missile, with a range of about 1,000 km.

The missile test brings Tokyo a step closer to fielding an indigenous family of long-range stand-off missiles that could be deployed from the land, sea and air, the Hong Kong-based South China Morning Post reported.

In his preface to the whitepaper, Japanese Defence Minister Shinjiro Koizumi hoped that it would “deepen the public’s understanding of Japan’s defence and security, and serve as an opportunity for people to reflect on how security is linked to the future of every citizen.”

“As the security environment rapidly intensifies, what is needed now is to enhance resilience to crises across the entire Indo-Pacific region,” Mr. Koizumi wrote, pledging to build and expand “a multi-layered network of allies and like-minded nations, and increase interconnectivity in all aspects, including training, troop deployment, equipment and industrial infrastructure, to improve deterrence across the region.”

Tension between China and Japan erupted in November over PM Sanae Takaichi’s remarks in parliament that a Taiwan contingency could be a “survival-threatening situation” for Japan that may lead to action from the country’s defence forces in support of the United States.

Her remarks angered China as it regards Taiwan as part of its territory and the relations remained tense since then.

“Stability around Taiwan is important for the international community, and our country needs to keep a close watch on the situation,” the white paper said.

On nuclear weapons, the paper reiterated Japan’s long-held three non-nuclear principles, saying that Tokyo continues to adhere to them “as policy guidelines.”

Mr. Koizumi, however, has appeared to set the stage for a review of the country’s decades-old pledge not to produce, possess or host nuclear arms, saying that the debate over nuclear weapons is the one “we cannot avoid”.