If you thought the drama in East Asia had cooled, think again. Japan is pressing ahead with plans to station missiles on Yonaguni, the tiny island a mere 11 km from Taiwan, and Beijing has responded with fury, calling Tokyo’s actions a dangerous provocation.
Defence Minister Shinjiro Koizumi visited Yonaguni on Sunday and made Japan’s position plain. The government intends to deploy medium-range surface-to-air missiles on the westernmost island of the Ryukyu chain as part of a wider military build-up across the southern islands. Koizumi argued the move is defensive: “The deployment can help lower the chance of an armed attack on our country,” he said, rejecting the idea it will heighten regional tensions.
Koizumi told Yonaguni’s mayor, Tsuneo Uechi, that plans are still being worked on and that Tokyo will share details with local officials and residents once the arrangements are finalised. He stressed the importance of local cooperation, noting Japan faces “the most severe and complex security environment since the end of World War II,” and framed the build-up as necessary to protect Japanese lives and peaceful livelihoods.
A frontline island
Yonaguni would effectively become a frontline of defence if Beijing ever moved militarily against Taiwan, which Beijing regards as a province that must be brought under its control. The deployment plans place the island at the sharp end of Tokyo’s strategy to deter threats across the southern island chain.
The island has not been without incident. In 2022, during Chinese military drills simulating the encirclement of Taiwan triggered by then-US House Speaker Nancy Pelosi’s visit, a Chinese missile landed just south of Yonaguni, a sharp reminder that these tensions are not theoretical for people living there.
Beijing’s angry response
China responded angrily to both the deployment plans and to recent comments by Japan’s new prime minister, Sanae Takaichi, who earlier this month raised the possibility that Japan might deploy its military to defend Taiwan in the event of a Chinese attack. Beijing said those remarks crossed a line.
Foreign Minister Wang Yi called it “shocking” that Japan’s leaders had publicly signalled a willingness to intervene in the Taiwan issue, accusing them of sending the wrong message and crossing “a red line that should not have been touched.”
On Friday, China escalated the diplomatic spat by sending a letter to UN Secretary-General António Guterres, in which China’s UN ambassador, Fu Cong, described Ms Takaichi’s remarks as a “grave violation of international law” and warned that any Japanese armed intervention would be considered “an act of aggression.” The letter said China would “resolutely exercise its right of self-defence under the UN Charter and international law” to defend its sovereignty and territorial integrity.
Japan’s foreign ministry rejected China’s claims as “entirely unacceptable,” saying Tokyo’s commitment to peace remains unchanged.
Cool shoulders at the G20
The tensions were visible at the G20 summit in South Africa, where Ms Takaichi and Chinese premier Li Qiang were at the same venue but did not meet. Ms Takaichi said she had not arranged a meeting and reiterated Japan’s willingness to hold dialogue while also stressing the need to be frank with China: “There are concerns and issues between Japan and China… That’s why we should work to reduce them, understand each other and cooperate more. Of course, it is important for Japan to say what needs to be said to China.”
Why this matters
This is not just diplomatic theatre. Yonaguni’s geography, once part of the Ryukyu Kingdom and incorporated into Japan as Okinawa Prefecture in 1879, makes it strategically important. Its proximity to Taiwan puts its residents and any deployed forces within immediate reach of cross-Strait tensions. Japan’s decision to move ahead with missile deployments marks a clear step in its post-war defence posture and is likely to increase friction with Beijing.
