Analytical extensions-themed posts expand on material that has appeared in another newsletter/section and other parts of this website more generally.
A previous post explained how the sharp downturn in bilateral relations between China and Japan following the political ascent of Sanae Takaichi, which comes amid an ever-intensifying military-technological competition between China and the United States, may lead China to, in effect, maximally turn the proverbial screws on Japan. One of the approaches that Beijing can undertake entails what is best understood as the activiation of the Sea of Japan threat vector, a dynamic of exceptional military signifiance that has long remained dormant not as a result of anything that Japan or the United States have done or could have done but because Beijing decided—out of self-interest—to restrict the geographic scope of China-Japan and China-United States military competition. While previous SPAS Consulting analyses have broached this topic, this post will offer a concrete example of one way China may activate the long-dormant Sea of Japan threat vector.
As explained in the first of the above posts, Japan is significantly closer to China’s northeast than the rest of the country:
A distance of just ~600 kilometers separates China’s northeastern Heilongjiang province from the northernmost tip of Hokkaido, while just ~700 kilometers separates said Chinese province from the southernmost tip of Hokkaido. Just ~750 kilometers separates China’s northeast from the northernmost tip of Honshu, while just ~810 kilometers separates China’s northeast from the westernmost point of Honshu. Tokyo is just ~1100 kilometers from China’s northeast, while the easternmost part of the Kanto Plain bordering the Pacific Ocean is around 1170 kilometers from China’s northeast. For context, Tokyo is around 1550 kilometers from the easternmost point of China’s Shandong Peninsula, while Tokyo is around 1750 kilometers from Shanghai. Sapporo, meanwhile, is over 1700 kilometers from the easternmost point of China’s Shandong Peninsula, while being over 2170 kilometers from Shanghai.
Given these distances, China can readily employ combat aircraft equipped with standoff land-attack and/or maritime strike munitions to target Japan’s western coast, as well as the rest of the elongated but quite narrow archipelagic country. There is, however, a catch:
China is separated from the Sea of Japan by a distance of just ~10.3 kilometers in orthodromic terms, with the Tumen River flowing for another ~16.5 kilometers from the easternmost point of the China-Russia border until it reaches the Sea of Japan.
By launching ballistic missiles and/or boost-glide vehicles (BGVs, also known as hypersonic glide vehicles, or HGVs) like the DF-17, China can overcome the fairly minor complication of having aircraft very briefly traverse North Korean and/or Russian airspace to reach the Sea of Japan, but China increasingly has an alternative: it can employ low-observable—so-called “stealth”—uncrewed aircraft to undertake such politically sensitive missions without putting at risk a Chinese pilot.
One example of such a Chinese uncrewed aircraft is the GJ-11, which was formally unveiled at a 2019 military parade in Beijing (the carrier-based naval variant, the GJ-21, was one of several large uncrewed aircraft designs displayed at the September 2025 military parade in Beijing).
A reusable armed uncrewed aircraft in the vein of the GJ-11 can be readily used—in time of war—to take off from one of several suitable Chinese airbases in the country’s northeast, transit through North Korean and/or Russian airspace for 2-4 minutes so as to reach international airspace in the Sea of Japan, and transit toward a pre-programmed position from which to launch stand-off munitions against Japan before returning to base and restarting the cycle.
Large uncrewed aircraft such as the GJ-11 can be employed in a manner that is conceptually akin to a reusable cruise missile that launches less expensive shorter-range strike munitions. The GJ-11 has previously been captured on satellite imagery at an airbase in the Himalayas near India, one of several sectors in which the GJ-11 and other Chinese uncrewed aircraft designs are likely to significantly enhance the reach and strike capabilities of the People’s Liberation Army Air Force (PLAAF) over the coming decade.
The activation of the Sea of Japan threat vector and the use of uncrewed aircraft like the GJ-11 to attack targets across the Japanese archipelago via the Sea of Japan is unlikely to constitute a silver bullet for China. Japan is, in both qualitative and quantitative terms, an immensely capable country, not least when it is allied to the United States, which has forward-deployed military forces in Japan and, as such, tremendous equities in the integrity of Japanese airspace. The activation of the aerial component of the long-dormant Sea of Japan threat vector, which has distinct air-to-air combat, terrestrial strike, and maritime strike components that are beyond the scope of this brief analysis, nevertheless has the potential to profoundly undermine Japanese security.
It bears emphasis that the potential activiation of the Sea of Japan threat vector will come at a time of intensifying military-technological competition between China and the United States, which is already stressing Japan’s ability to keep up in, among areas, air-to-air combat capabilities and naval air defence capabilities, areas in which the potential deployment of uncrewed aircraft such as the GJ-11 above the Sea of Japan is likely to only compound the immense challenges that Japan already faces.
