The US sent China a hard-to-miss message Tuesday—in the form of a naval destroyer—that it thinks Beijing is over-reaching in its claim of disputed waters in the South China Sea. The USS Lassen sailed close to manmade islands constructed by Beijing, and China says it monitored and warned the ship, reports the AP. (It's not clear whether a Chinese vessel actually followed it.) The Lassen came within 12 nautical miles of the islands in the Spratly archipelago, making clear that the US doesn't recognize Beijing's sovereignty there. China's foreign ministry called it a "deliberate provocation" and warned that the move could backfire. "It would be a pity for us to realize that we have to strengthen and speed up relevant construction activities," says a spokesman.
Still, the New York Times characterizes that as a "relatively mild response," at least so far. The big question is whether the increasing tensions will lead to more than just symbolic gestures and warnings, especially because the US plans more such trips in the coming weeks, according to Reuters. "China will have to react—it cannot not react to this," a professor at Singapore's Institute of South East Asian Studies tells the Guardian. "Nationalism in China is such that China will be expected to make a robust response to this." (Read more China stories.)