In May 2016 Chinese warships in the South China Sea were seen practicing detailed exercises for halting merchant ships and boarding them. China claims to control all of the South China Sea but the rest of the world does not agree with that. The May exercises are another sign that China does not care what the world thinks. In one part of the exercise the intercepting destroyer fired its guns, as it would to force a ship that refused orders to halt and be boarded. This is all part of a trend that is not going anywhere good.
Already commercial airlines are complying with Chinese demands (which have no legal standing) that aircraft check in with Chinese air control before entering formerly international airspace now claimed by China. Now it is feared China will demand the same compliance from commercial shipping. Efforts to control foreign fishing boats have met a lot of opposition but owners of the big tankers and cargo ships are expected to just go along. The Chinese want to establish a history of other nations accepting Chinese claims so that when the Chinese to use force to control who enters the international waters of the South China Sea the only way to stop that will be for foreign warships to attack the interdicting Chinese warships. China believes no country will be able to resist this gradual assertion of control.
Yet there is resistance. Starting in early 2015 the U.S. said it would send warships into the South China Sea at least twice every three months from then on. Those ships deliberately challenge Chinese claims to own the South China Sea. China believes it can handle these American intrusions without triggering a disastrous (especially for China) war because the U.S. Navy only has 55 warships assigned to the West Pacific while the China has 116 warships assigned to its southern fleet plus 200 large (over 500 tons) seagoing coast guard vessels in the area. Plus China can use Chinese commercial vessels to help out. China uses all these ships to aggressively confront American (or any other) ships that come close to Chinese ships or claimed territory in the South China Sea. This sort of aggressiveness has not been experienced by American warships on such a scale since the Cold War when Russian warships would risk collision in what American sailors came to call "Chicken Of The Sea." All this is reminiscent of Cold War incidents, usually involving Russian ships harassing American ships by moving very close, or even on a collision course. This was all for the purpose of interfering with U.S. intelligence operations, especially those off the Russian coast. Earlier in the Cold War Russian warplanes would fire on American intelligence gathering aircraft, shooting some of them down. This sort of thing declined when the U.S. quietly informed the Russians that American warships and combat aircraft would aggressively return fire. By the end of the 1960s, this aggressive activity diminished to the point where it was considered a minor nuisance and even that was eliminated by a 1972 treaty. The same pattern is playing out with the Chinese but for the last few years the Chinese have continued to protest American intelligence gathering activity so close (up to 22 kilometers from Chinese territory, an area that is considered “territorial waters”) as well as the South China Sea operations. Long term China believes it can win this war of wills.