China has been raising blood pressures for some time over its actions in the South China Sea.  From its aggressive advocacy of territorial and jurisdictional claims to its expansive land reclamation activities, there are “serious questions about Chinese intentions,” says Adm. Harry Harris, Commander of United States Pacific Command.

However, the attention given to events in the South China Sea may soon shift north, as China and Japan slowly ramp up pressure on each other in the East China Sea. Three recent developments have the potential to escalate tensions between these Asian powers—and due to its alliance commitments to Japan, the United States as well.

Beijing and Tokyo’s territorial dispute over the Senkakus (Diaoyu in Chinese) is nothing new. China disputes Japan’s claim that, in the closing days of the Sino-Japanese War, the islands were terra nullius—no man’s land—and Tokyo had the right to incorporate them. Tensions over the islands have grown in recent years, after a Chinese fishing trawler intentionally rammed two Japan Coast Guard vessels in 2010, and Tokyo purchased some of the islands from their private owners in 2012. An outburst of provocative Chinese military and coast guard activity in the skies and waters around the islands followed these events. These activities have since become commonplace. In other words, a tense new normal was established, but it is increasingly stressed by three developments.

The first is China’s construction of two, massive coast guard vessels. Since the China Coast Guard was established in 2013, it has grown to become a key tool in pursuing China’s maritime claims. Toward that end, it commissioned a host of new ships, the most significant being two, high-endurance surveillance ships. Each will reportedly have a 10,000-ton displacement (closer to 15,000 at full load), making these ships the largest coast guard vessels in the world.

Heretofore, the largest surveillance ship was Japan’s Shikishima-class, which has a 6,500-ton displacement (about 9,000 tons at full load). Importantly, unlike most China Coast Guard ships, which are usually unarmed, China’s new ships will be outfitted with firepower (one 76-millimeter cannon, two 30-millimeter guns) and capable of carrying two, multi-role helicopters. One ship is already completed, the Zhongguo Haijing 2901; the second one is in the latter phase of construction.

The second development is that China reportedly plans to build two bases close to the disputed Senkaku Islands. Japan’s Yomiuri Shimbun reported that the China Coast Guard is considering construction of a large operating base in China’s port city of Wenzhou to enhance surveillance of the islands. The base, about 350 kilometers from the islands, will reportedly be about 500,000 square meters, with a large hangar for airplanes or helicopters, a training facility and a pier over 1.2 kilometers long, capable of mooring six ships—including the Zhongguo Haijing 2901.

News of this project follows reports that China’s military is constructing a large base on Nanji Island, only 300 kilometers from the Senkakus. Photographs show wind turbines, several large radar installations and a heliport with 10 landing pads, most likely to be used by helicopters operating on naval or China Coast Guard ships. Although airstrips are not being constructed, the military already has an airfield in the town of Luqiao, roughly 380 kilometers from the disputed islands.

Third, if big ships and new bases were not enough, just over 180 kilometers northeast of the Senkaku Islands sit oil and gas fields. But it is not the existence of these fields that is the issue; rather, it is efforts to extract resources from them.

Currently, there are 16 Chinese structures engaged in offshore oil and gas activities in the East China Sea. Twelve have been constructed since 2012. In 2008, Beijing and Tokyo agreed they would cooperate on the joint development of East China Sea resources, but Tokyo is now crying foul because it believes the drilling rigs demonstrate China’s unilateral activities.

Beijing disagrees. Although they have differing exclusive economic zone claims, these structures remain on Beijing’s side of the median line proposed by Japan, meaning that China’s activities remain within the undisputed waters of its EEZ. Japan’s concern is that China is tapping into resources under Tokyo’s EEZ, because these structures are close to the median line.

To draw attention to this concern, the Japanese government released aerial photos of these projects and a detailed map of their locations, calling on China to reconsider these activities. In response, China bemoaned Japan’s actions as not being constructive to the management of East China Sea issues, particularly since the structures have been there for two years.

These three developments have the potential to change bilateral dynamics. The new ships improve the China Coast Guard’s maritime strength, thereby enabling China to perform “rights protection” operations far from shore and drive away smaller ships. What is more, the armaments signal that the China Coast Guard is willing to engage other ships aggressively. In turn, this places the Japan Coast Guard in a predicament. If confronted by the 2901, will a Japan Coast Guard ship accept its movements and turn away, or stand firm and risk escalation? The former sets a potentially negative precedent for Japan; the latter risks a conflict that could draw in the United States due to its alliance commitment to Japan.

Similarly, the new bases strengthen China’s ability to conduct surveillance over the disputed Senkakus on a continuous basis. Of particular importance is the fact that both bases are closer to the islands than U.S. and Japanese forces stationed on Okinawa, which is 400 kilometers further north. Beijing is positioning itself to be able to test Japan’s administrative control through its military and coast guard. If Japan attempts to match China’s greater presence, the risks of accidental collision or conflict increase. If Japan continues operations at current levels, it risks the appearance of ceding ground to China. Or worse. Japan’s position to demonstrate administrative control over the islands is jeopardized.

Finally, Chinese oil and gas structures in the East China Sea open up a new front in the maritime dispute that has largely focused on ownership of the islands. While it is unlikely China will stop its activities on its side of the Japanese proposed median line, relations could plummet if Japan responds by moving in resource extraction equipment on its side. In turn, these moves could force both countries to deploy their militaries or coast guards to protect their equipment, thereby expanding the maritime/aerial cat-and-mouse games—so prevalent around the Senkakus—further north. Just as destabilizing would be if China starts to actively ignore the median line and attempts to enforce its EEZ claim extending to the Okinawa Trough, based on the natural extension of its continental shelf. Similar to the South China Sea, the East China Sea would effectively become a Chinese lake, something Japan would never accept.

This all bodes poorly for regional security. What is worse, it leaves the United States in a bind. If any one of these scenarios came to pass, Washington would be left with a very difficult problem. Is it willing to use military assets to protect a handful of uninhabited islands and risk large-scale war with China? Or is it willing to sacrifice its alliance with Japan and, thereby, call into question its commitments worldwide in order to avoid conflict with China?

There are no easy answers.  But the problem highlights a critical point. While the world remains transfixed on events in the South China Sea, developments in the East China Sea demand attention, sooner rather than later. Unfortunately, the new normal may already be a thing of the past.

Jeffrey W. Hornung is Fellow for the Security and Foreign Affairs Program at Sasakawa Peace Foundation USA in Washington, D.C.

Image: Wikimedia/Japan Maritime Self-Defense Force