A comparison of satellite images taken in May 2024 and September 2025 shows that construction of Japan's military base on Mageshima Island has accelerated significantly.

Exclusive satellite images recently obtained by the Global Times show that Japan is rapidly advancing military construction on Mageshima Island, a key strategic location in the southwestern region of Japan. Multiple military facilities have taken shape on this uninhabited island in just one year, with the outline of a full-scale base already emerging.

Japanese Prime Minister Sanae Takaichi recently made erroneous remarks concerning Taiwan question, drawing widespread criticism from the international community. Yet behind these provocative statements, the Japanese government has been accelerating its military expansion, particularly by strengthening deployments across the southwestern islands. According to Japanese media, the Japan Self-Defense Forces established a garrison on Ishigaki Island in the southwest as early as 2023, deploying Type 12 ground-launched, anti-ship missile and Type 03 medium-range surface-to-air missiles. After Takaichi took office, Japanese Defense Minister Shinjiro Koizumi, during a visit to Yonaguni Island—Japan's westernmost island located close to Taiwan—announced that Japan would proceed as planned with the deployment of Type 03 medium-range air-defense missiles there.

Public reports indicate that Mageshima Island sits at the mouth of the strategically important Osumi Strait and controls a key maritime route. The island covers roughly 8.2 square kilometers. In 2019, the Japanese government purchased the island for 16 billion yen, with the primary goal of turning it into an "unsinkable aircraft carrier." Construction officially began in January 2023.

Two high-resolution satellite images obtained by the Global Times—captured by Chinese commercial satellites—show that Mageshima Island, Japan's second-largest uninhabited island, has effectively transformed into a massive construction site. The two images were taken in May 2024 and September 2025. In the May 2024 image, large main structures were barely visible, whereas by September 2025, the outline of an airstrip under construction could be clearly seen. The number of support vessels surrounding the island had also increased significantly.

Satellite image, combined with open-source information, shows that the functional layout of the Mageshima Island military base is becoming increasingly clear, with major facilities such as ammunition depots, an airfield, fuel storage, and a pier already taking shape.

 
Analysts told the Global Times that by comparing the satellite images with open-source information, it is evident that construction on the Mageshima military base has accelerated markedly. At present, major military facilities—including a 2,000-meter runway, ammunition depots, fuel infrastructure such as storage tanks, and a temporary pier capable of accommodating large warships—have already taken shape. The functional layout of the entire Mageshima military base is now clearly visible.

In a report on facility construction on Mageshima Island recently released by Japanese defense ministry, it is openly claimed that developing Mageshima Island into a military base is to respond to countries in the surrounding region, including China, that possess advanced and strong military capabilities. Mageshima is intended to serve as a training and operational base for the Japan Self-Defense Forces, it said.

Japan will construct two aircraft runways and related supporting military facilities on Mageshima Island, said the report. In peacetime, the base will be used for routine takeoff and landing training of F-35, F-15, and F-2 fighter jets, and will also serve as a training base for carrier-based aircraft, including F-35B operations. In wartime, Mageshima Island could function as an important staging area and logistical support base.

One scholar claimed that "Since one of the main strategic objectives of the Japanese Ministry of Defense is to strengthen the defense of the southwestern islands and to establish an appropriate and fast supply system in the region, Mageshima is suitable for playing this important role." He added, "With Mageshima prepared, the SDF and the US Forces in Japan will be able to take advantage of it to increase the depth of defense and keep China's activities in the area in check."

"Turning Mageshima into a military base can be seen as Japan's preparation for military involvement in the Taiwan question — and it is a crucial step," Chinese military affairs expert Zhang Junshe told the Global Times. He noted that the current Japanese government has formulated a strategy of strengthening "offensive defense" across the southwestern islands, with Mageshima being a key component. The military base under construction there serves multiple purposes, all of which, he stressed, are directed at China.

He further explained that one function of the Mageshima base is to reinforce Japan's control over the Osumi Strait. In a wartime scenario, Japan could use the base to block the strait in an attempt to prevent the Chinese Navy from passing through this international waterway.

In addition, Japan plans to use Mageshima Island as a routine training base for F-35B carrier-based aircraft. But in wartime, the island could serve as a "springboard," enabling F-35Bs to take off directly from Mageshima Island to threaten Chinese vessels and aircraft operating in the East China Sea or even targets along China's eastern coastline, according to Zhang.

During World War II, the Japanese militarist government pursued a strategy of fortifying the Pacific islands it had occupied to carry out its external aggression and expansion. Zhang said that Japan's current militarization of uninhabited islands like Mageshima Island is, in fact, a replication of the practices employed by the Japanese military during World War II. "Japan's current adoption of the 'island hopping' tactic, while intended to align with the US concept of maritime distributed operations, amounts to a continuation of the tactics employed by the Japanese military during World War II. However, Japan is now 'arming' the Ryukyu Islands with the aim of threatening China. Such actions by Japan not only violate the spirit of the pacifist Constitution, but also seriously contravene the Potsdam Proclamation, which stipulates that Japan shall not be permitted to 're-arm for war'," stated Zhang.

Earlier, Mao Ning, a spokesperson of Chinese Foreign Ministry, has noted that Japan's deployment of offensive weapons in Southwest Islands close to China's Taiwan region is a deliberate move that breeds regional tensions and stokes military confrontation. Given Japanese Prime Minister Sanae Takaichi's erroneous remarks on Taiwan, this move is extremely dangerous and should put Japan's neighboring countries and the international community on high alert.

Mao further noted that The Potsdam Proclamation explicitly stipulates that Japan shall not be permitted to "re-arm for war." The Japanese Constitution, which enshrines pacifism, also established Japan's exclusively defense-oriented policy. It is alarming, however, that in recent years, Japan has drastically readjusted its security policy, increased defense budget year after year, relaxed restrictions on arms export, sought to develop offensive weapons, and planned to abandon its three non-nuclear principles. Japan's right-wing provocateurs are trying every means to break free from the pacifist constitution, going further down the path of military buildup and leading Japan and the region to disastrous outcomes.

This year marks the 80th anniversary of the victory of the Chinese People's War of Resistance Against Japanese Aggression and the recovery of Taiwan. China will never allow Japan's right-wing provocateurs to turn back the wheel of history, never allow external forces to lay their hands on China's Taiwan region, and never allow the resurgence of Japan's militarism. China is resolved in and capable of defending national and territorial sovereignty," said Mao.

"If Japan dares to intervene militarily in the Taiwan question, we believe the People's Liberation Army（PLA）has sufficient strength and means to eliminate these so-called 'unsinkable aircraft carriers'," said Zhang, stating that the military parade marking the 80th anniversary of the victory in the Chinese People's War of Resistance against Japanese Aggression and the World Anti-Fascist War held on September 3 this year has showcased the PLA's abundant strategic strike capabilities. The land-based, sea-based, and air-based hypersonic missiles, along with various medium-range and short-range missiles displayed during the parade, are all capable of delivering devastating strikes against such militarized and fortified islands.

"If Japan dares to intervene militarily in the Taiwan question, it would constitute a challenge to China's core interests. I believe that under the saturation strikes of the PLA, these so-called 'unsinkable aircraft carriers' painstakingly built by Japan would be completely incapacitated. China's principles are very clear: we will not fire the first shot, nor will we allow Japanese forces the chance to fire a second, and we absolutely will not permit resurgent Japanese militarism to run rampant as it did during World War II," said Zhang.