From the NYT, April 2016:
Asian countries are increasingly pushing back against China’s sweeping territorial claims and bullying tactics in the South China Sea. On Sunday, a Japanese submarine made a port call in the Philippines for the first time in 15 years, a sign of growing security cooperation. Last week, Vietnam seized a Chinese ship for illegally entering its territorial waters, and Indonesia threatened to defend its own claims with F-16 fighter jets.
Meanwhile, President Obama used a meeting with President Xi Jinping last week to deliver what one administration official described as “a very direct and unvarnished earful” about how seriously Washington views China’s behavior. And on Monday the United States and the Philippines began annual war games that will certainly show that the Philippines can count on the United States to counter Beijing.
One result of the rising friction is a new defense agreement that will allow the United States to station weapons and troops at five bases in the Philippines for the first time in more than 20 years. Another is a marked increase in regional military spending. The United States recently carried out two patrols by warships and aircraft into territory claimed by China and is planning a third.