Chinese warships frequently pass through narrow Strait of Japan, experts warn: gray zone operation

In recent years, China has often sent warshipsJapan In the waters around the Southwest Islands, Katsuya Yamamoto, leader of the Strategy and Deterrence Research Group of Japan’s Sasakawa Peace Foundation and chief researcher, said today that the biggest security challenge facing Japan is not a potential military conflict in the future, but China’s ongoing “gray zone” activities, and it is necessary to be careful to prevent uninhabited islands from becoming the first island chain gap.

Masaru Yamamoto held a press conference at the Foreign Correspondents’ Association of Japan (FCCJ) and said that China’s security strategy is fundamentally different from that of Japan and Western countries. China has long adhered to the concept of “people’s war” and mobilized private enterprises, shipping companies, port operators and other social resources not only during war, but also during peace. He called this concept “people’s war at sea”.

He cited as an example the Chinese Navy’s repeated passage through the Hengdong Strait near Amami Oshima in Japan’s Kagoshima Prefecture. He told that this strait is narrow and its geographical environment is complex. In terms of navigation safety and efficiency, it is much less convenient than the Osumi Strait or Miyako Strait. Even the Japan Maritime Self-Defense Force rarely uses it as a daily navigation route. However, Chinese warships continue to choose this route. He believes that there are strategic considerations behind this.

Yamamoto analyzed that in addition to allowing China to become familiar with the local marine environment and observe Japan’s monitoring and warning activities, it could also cause psychological pressure on nearby residents. More importantly, these activities will help gradually make the presence of Chinese military forces around Japan’s southwestern islands a norm.

He explained that “what seems unusual today may be routine tomorrow.” This method of gradually changing the status quo and perceptions without crossing the threshold of armed conflict is a distinctive feature of “gray zone” strategy. In other words, the purpose of the voyage of these warships is not just simple navigation. Instead, it has, through repeated passage, gradually shaped a strategic environment that is favorable to China.

Yamamoto pointed out that China proposed the concept of “Shield of Justice” during the “Justice Mission 2025” military exercises late last year. Its strategic goal is not just to block Taiwan, but to control Japan’s southwestern islands, the entire first island chain from Taiwan to the Philippines, and prevent US forces and allies from intervening.

He said China could use its “anti-access/area denial” (A2/AD) strategy to prevent US and allied forces from approaching Taiwan. If China wants to prevent the United States, Japan and other countries from supporting Taiwan, it will inevitably try to increase its influence on the islands in the first island chain. Therefore, those that really deserve caution include the southwestern islands of Japan where the Self-Defense Forces are not permanently deployed and uninhabited islands.

Yamamoto analyzed that the Chinese military often made repeated sailings around these islands, possibly using them to understand the terrain, maritime environment, and entry and exit routes. Once a crisis occurs, China could use its existing experience to deploy unmanned systems with less warning, or even send special forces to the island.

Regarding the ongoing “Sharp Sword” joint military exercises between Japan and the United States, Yamamoto said China continues to closely observe the joint training between the Japanese Self-Defense Forces and the US military. Therefore, demonstrating the cooperation capabilities of both countries through repeated exercises can have a powerful deterrent effect at the military and practical level.

However, he stressed that in the face of China’s gray zone activities against Japan, Japan should still have the ability to respond independently, and the United States should play a supporting role.

He advocated that Japan should increase its economic, technological, and military influence and not rely solely on the United States. Instead, it should strengthen cooperation with the EU, NATO, Taiwan, the Philippines, and other partners who share values ​​to further enhance Japan’s influence over the United States and other major powers.