In the East China Sea, Beijing Tests Japan’s Resolve Analysis in The Stratfor, Feb 3, 2016

Summary
China’s long-standing rivalry with Japan in the East China Sea is heating up once again. In addition to their standing disputes over the Diaoyu/Senkaku Islands and Beijing’s attempts to break through the first island chain, it is looking more and more likely that Japan will wade into the South China Sea conflict as well. In response, China is turning to new capabilities and tactics in the East China Sea in an attempt to outmaneuver its Japanese adversary — and to remind Tokyo that interfering in the South China Sea will have consequences closer to home.
Analysis
In November 2015, Japanese Prime Minister Shinzo Abe announced that his country would consider sending the Japanese Maritime Self-Defense Force on patrols in the South China Sea. Meanwhile, Japan has been building up its relationships with Vietnam and the Philippines, both of which contest China’s territorial claims in the South China Sea. In fact, Tokyo has taken steps to explore a visiting forces agreement with Manila that would allow Japanese ships and aircraft to refuel in the Philippines and let Japanese military personnel use Philippine bases on a rotational basis.
Conversation: Why the South China Sea Is So Contentious
China has been watching these developments with growing concern. Beijing has tried to persuade the United States to pressure Japan to stay out of the South China Sea, but it is simultaneously searching for alternative strategies to convince Tokyo to withdraw from the area. One of the most important components of those efforts will be to turn the tables on Japan by ramping up its own presence in the East China Sea. Over the past few months, China has kept up the pace of its incursions into the disputed waters around the Diaoyu/Senkaku Islands, and Chinese flights have penetrated Japan’s East China Sea air defense identification zone in droves.
Beijing may also turn to its coast guard to make more assertive maneuvers in the East China Sea. The tactic is commonly used among the many claimants in the East and South China seas. Coast guard vessels are different from naval vessels, often identified by their white-painted hulls, and they can declare or defend territorial rights without the involvement of warships, which can significantly raise the risk of miscalculation and escalation in contested waters. The Chinese have used their coast guard and other maritime militia vessels with success before, including against the Philippines near the Scarborough Shoal in 2012. However, given Japan’s own powerful coast guard, Tokyo will likely continue to have the upper hand in the Diaoyu/Senkaku Islands.
Still, this may not be true for long. China is seeking to break Japan’s dominance with several new maritime capabilities. First, Beijing is transferring frigates that formerly belonged to the Chinese navy to its coast guard. While the bulk of these vessels’ armaments have been removed, their true threat lies in their high speeds and strong hulls — virtues of setting industry specifications to a military’s standards. Second, Beijing has commissioned the construction of gigantic new vessels for its coast guard. While size and hull strength are generally poor indicators of capability when it comes to modern naval warfare, they can still provide a decisive advantage in skirmishes between coast guards, where tactics like shouldering and ramming are the most common offensive maneuvers. China’s newly commissioned 10,000-ton cutters are large, powerful and nearly double the size of Japan’s 6,500-ton Shikishima-class cutters (which were, until now, the largest coast guard vessels in the world). This will make it all the more difficult and dangerous for Japanese ships to try to shoulder away China’s enormous vessels.
Of course, Japan is taking steps to counter China’s moves. The Japanese Air Self-Defense Force is continuing to build up its presence at the Naha airfield in Okinawa, including the establishment of a new air wing. The unit has doubled the number of available F-15J air superiority fighters in Okinawa to 40, enabling the Japanese to better respond to China’s growing air activity in the East China Sea. In 2015, Chinese air activity triggered 441 Japanese scrambles, twice the number in 2011. At the time, the heightened frequency of flights threatened to overwhelm Japanese forces, which had not yet received the Okinawa reinforcements.
Japan is also making preparations to ramp up support to its coast guard. In January, Japanese Chief Cabinet Secretary Yoshihide Suga made it clear that Abe is ready to mobilize the Japanese Maritime Self-Defense Force in the event that a situation arises that the coast guard cannot cope with. Japanese Defense Minister Gen Nakatani echoed the statement by broaching the possibility of allowing the Japanese Maritime Self-Defense Force to carry out policing activities.
As both sides ratchet up their involvement in the South and East China seas, the potential for conflict will increase. Clashes between coast guards — especially those with greater capacities for inflicting damage — could pull navies into the fray. Meanwhile, the skies above the disputed seas will be just as fraught as the rising tempo of air intercepts, especially between Japanese and Chinese aircraft, will increase the risk of an accident or miscalculation that could ignite a wider conflict. https://www.stratfor.com/analysis/east-china-sea-beijing-tests-japans-resolve?login=1