In an interview today with the BBC, Secretary of Defense Ash Carter threatened further US military involvement in the South China Sea, saying nothing would stop the United States from carrying out overflights and naval patrols through the area as they have for years.

The comments are a continuation of increasingly bellicose US rhetoric against China over the construction of artificial islands in the Spratly chain. China is one of several nations with competing claims in the Spratlys, and the US has claimed China’s land reclamation program threatens a regional war.

Chinese Admiral Sun Jianguo downplayed the seriousness of the situation in his own comments this weekend from Singapore, saying the artificial islands were not targeting any other country’s claims, and would not interrupt freedom of navigation for ships through the South China Sea.

Sun insisted that the construction was entirely legitimate and reasonable. There is no problem under international law with construction of islands, despite the US objections, and many Chinese officials believe the Pentagon is blowing the situation far out of proportion.

On the other hand, Sun did not rule out setting up an airspace defense region over the new islands, saying that would depend on if the islands were facing any airborne threat. The Pentagon’s efforts to publicly and repeatedly overfly the islands seem designed around the idea that they’re going to coax China into such a move so they can denounce and respond to it.