Senkaku Islands (尖閣諸島). China calls it Diaoyu Islands (钓鱼岛) whereas Japan calls the disputed islands Senkaku Islands (尖閣諸島).

The Japan Coast Guard reported on July 22 that Chinese patrol ships had navigated within the 24-nautical mile contiguous zone around the Senkakus for 100 straight days, the longest streak since at least 2012, when the Japanese government nationalized some of the islands. And China Coast Guard ships have pursued Japanese fishing vessels within the 12-nautical-mile territorial sea around the islands twice in the past three months. That had only happened four other times over the past seven years, according to the Japan Coast Guard. Though the size and frequency of Chinese patrols are unchanged, their duration and assertiveness appear to have shifted in recent months.

Japan faces a losing proposition if it tries to maintain control over the waters around the Senkakus with ships alone. It cannot build them as quickly as China is. Nor can its coast guard vessels compete with the latest Chinese models on size and armaments. Instead Japan is looking to turn geography to its advantage. In recent years, Tokyo has invested in capabilities in its nearby Southwest Islands to better monitor and defend the waters around the Senkakus from land. AMTI last examined Japan’s efforts in 2017. At that time, most of the upgrades focused on better radar, signals intelligence, and patrol capabilities. Missile units were planned but not yet established. Since then, Japan has made substantial progress on existing plans and launched new initiatives.

One of the primary measures Japan has taken to enhance its island defense capability has been the deployment of anti-ship and surface-to-air (SAM) missiles throughout the island chain. In addition to a SAM unit deployed to Okinawa, Japan has recently constructed facilities and activated new units to facilitate missile deployments to three other islands: Amami Oshima, Miyako, and Ishigaki.

On March 26, 2019, the Japan Ground Self Defense Force (JGSDF) activated two new camps on Amami Oshima that it had begun constructing in 2016. Camp Amami (left, below) houses a 350-troop SAM unit equipped with Type 03 “Chu-SAM” missiles. Camp Setouchi (right, below) is home to a 210-troop unit equipped with Type 12 surface-to-ship missiles.

The JGSDF also activated a new camp on Miyako in March 2019, deploying 380 troops as the Miyako Area Security Force. In March 2020, anti-ship missile and SAM units were deployed to the camp, though the missiles themselves have yet to arrive. Concerns have been raised over plans to store them at an ammunition depot six miles from their launchers.

On the island of Ishigaki, land clearing began in 2019 for a site to host SAM and anti-ship missile units. Construction is ongoing as of summer 2020, with plans to deploy missile units before 2023. The Senkakus are nearly 200 nautical miles from the Chinese coast but less than 100 nautical miles from Ishigaki and Miyako. That places them within range of anti-ship cruise missiles on those islands.

Japan is also looking to upgrade the capabilities of these missile units. The Japan Maritime Self-Defense Force is reportedly testing an air-launched variant of the Type 12 anti-ship missile designed for P-1 maritime patrol aircraft which would extend the missile’s range to 160 nautical miles. The Ministry of Defense is also developing a hypersonic anti-ship missile which it plans to deploy by 2026 for the defense of Japan’s “remote islands.”