Mounting tensions over the disputed Senkaku Islands have been a constant in Sino-Japanese relations since Tokyo purchased three of the five islands in 2012. For the last four years, Chinese coast guard vessels have regularly patrolled in the vicinity of the East China Sea islands and have often entered within the 12-nautical-mile territorial sea around the Senkakus, engaging in a cat-and-mouse game with their Japanese counterparts tasked with maintaining Tokyo’s control over the features. Meanwhile, People’s Liberation Army Air Force (PLAAF) patrols around the Senkakus and Japan’s southern islands have led to regular scrambles by the Japanese Air Self Defense Force.

It is easy to assume that tensions in the East China Sea have settled into a new equilibrium, with developments in the South China Sea dominating international headlines. But the relatively quiet, if still tense, status quo around the Senkakus masks worrying trends that suggest a new, more dangerous phase of the dispute could be on the horizon.

CSIS Senior Vice President for Asia and Japan Chair Michael Green provides an overview of the evolving situation in the East China Sea below.

Big and Bigger Ships


Patrols by Chinese government and nongovernment vessels within the territorial sea around the Senkakus spiked dramatically in late-2012 and 2013. The absolute number of patrols fell a little more than a year after Tokyo’s purchase of the islands, but remained dramatically higher than pre-2012 levels. Now Chinese entry into the Japanese-administered waters around the Senkakus has become a regular affair, with a dedicated patrol unit of the Japan Coast Guard (JCG) often responding to multiple groups of China Coast Guard (CCG) or other affiliated ships entering the territorial sea in a single day.

Graph of Incursions
Graph of Incursions

 

The CCG is highly experienced at entering Japanese waters to challenge sovereignty while avoiding a serious confrontation. Likewise, the JCG is highly professional and experienced at avoiding escalation with its Chinese counterparts. But these competing patrols still bear risks due to the unknowns—whether a technical malfunction in contested waters, a misread signal, an accidental collision, or the intervention of protestors or rogue fishermen could cause an otherwise routine encounter to spin out of control.

More worrying over the long-term is that, while the total number of Chinese ships patrolling the Senkakus has been relatively constant, their size is steadily increasing. According to data released by the CCG, the ships it sent to the Senkakus in 2014 displaced an average of about 2,200 tons. In 2015, that average had grown to over 3,200 tons.

Coast Guard Assets
Coast Guard Assets

 

Much has been made of the Haijing 2901 – a new CCG ship displacing over 10,000 tons, which was deployed to the East China Sea in 2015 and is expected to join patrols around the Senkakus in the future. This would be the largest coast guard vessel in the world, rivaled only by its sister ship, the Haijing 3901, which is set to patrol the South China Sea in the coming years. These ships are larger than a U.S. Arleigh Burke-class destroyer. They are also much better armed than most coast guard vessels, though in the law enforcement field, where ramming or shouldering is more likely than an exchange of fire, the extra mass alone could tip the balance in any contest.

 

Naval Vessels Turned Coast Guard


China has modified several naval warships and redeployed them as coast guard ships to help patrol the Senkakus. By removing their anti-ship and surface to air missiles, alongside their heaviest guns, these former navy ships-still better armed than most coast guard vessels-give China a sizeable advantage in standoffs with other law enforcement ships

Coast Guard Ships Deployed
Coast Guard Ships Deployed

 

Three ship classes have been modified to act as law enforcement vessels, each averaging a medium-to-high tonnage when compared to the other 11 classes of cutter which China sends to the Senkakus. Amid China’s ongoing overhaul of its military and the 2013 consolidation of its maritime law enforcement agencies into the unified CCG, these transfers and the construction of newer, larger patrol vessels show that Beijing is making its coast guard buildup a strategic priority.

 

More Frequent Air Patrols


Japan is scrambling its fighters at Cold War levels in response to intrusions by both Russian bombers from the north and Chinese combat aircraft in the south.

JASDF Scrambles by Region
JASDF Scrambles by Region

 

In FY2014, Japan scrambled its fighters 943 times — on par with its previous record set in 1984. Half of these scrambles were made against targets in the area southwest of Kyushu, nearest the Senkaku Islands. Chinese aerial incursions have been steadily rising since 2012, with PLAAF aircraft increasingly willing to test the limits of their Japanese counterparts. In 2014, two Chinese Su-27 fighters came within 100 and 165 feet, respectively, of two Japanese military aircraft inside the overlap between the Japanese and Chinese Air Defense Identification Zones (ADIZ) over the East China Sea. Such dangerously close approaches are not the norm, but highlight the possibility that frequent scrambles could eventually lead to an accidental midair collision. The Chinese ADIZ, declared in late 2013, has bolstered China’s aerial presence in the region. And while Beijing has reportedly only enforced the zone once, and not against Japanese aircraft, any attempt to do so in future could provoke a crisis.

 

Japan Responding – In a Big Way


Japan is not sitting idle. Tokyo understands that the increasing size and capabilities of CCG vessels around the Senkakus present a unique challenge—sooner or later JCG counterparts could face a situation in which they cannot maintain their decades-long administrative control over the waters around the islets, at least without assistance from the Japan Maritime Self-Defense Forces (JMSDF). That would signal a major shift in the status quo. In preparation for such an eventuality, and presumably to deter against China employing naval vessels first, Chief Cabinet Secretary Yoshihide Suga said on January 12 that under a new policy, JMSDF assets could engage in “maritime policing operation[s]” if foreign warships enter Japanese territorial waters under a pretense other than “innocent passage.” It is still unclear whether this could apply to repurposed PLAN ships now in the CCG.

Japan has also begun to boost its maritime domain awareness and military capabilities around the disputed islands, opening a radar station on Yonaguni (90 miles south of the Senkakus), deploying additional troops to the Amami Islands near Okinawa, and preparing a multiphasic plan for an amphibious military response to any threat to Japan’s continued administration of the Senkakus. The JCG unit dedicated to patrolling the Senkakus has also been bolstered with 10 new 1,500-ton patrol ships and two helicopter-equipped vessels, deployed in early April to prevent the need for other coast guard units to help respond to Chinese patrols, as has been the case in recent years.