The United States has good reason to push back more forcefully against China’s grab for power in the South China Sea, as Defense Secretary Ashton Carter did on a trip to Asia this week. Beijing has repeatedly ignored earlier warnings to moderate the aggressive behavior that is unsettling its regional neighbors and further undermining its relations with the United States.

On Friday, American officials disclosed that China had installed two mobile artillery vehicles on an artificial island it is building in the sea, which is rich in natural resources like oil and gas and where China clearly hopes to establish some form of hegemony.

The weapons are not considered a threat to American naval forces. Still, they reinforce fears that China intends to militarize the Spratly Islands, a collection of reefs and rocks also claimed by the Philippines, Vietnam, Malaysia and Taiwan, and use them to control the waterway’s shipping lanes and dominate its smaller neighbors.

Read more: http://www.nytimes.com/2015/05/30/opinion/pushback-in-the-south-china-sea.html?_r=1