|The Subi Reef in the Spratlys|
The Chinese claims surround man-made islands which are not under the United Nations Convention on the Law of the Sea. However, this did not stop China from using strong language and shadowing the USS Lassen. A reuters article cites the Chinese Defense Ministry stating, the US patrol was a "coercive action that seeks to militarize the South China Sea region" and an "abuse" of freedom of navigation under international law.
This is interesting as it was just 6 weeks ago that the Chinese sailed within 12 nautical miles of the American controlled Aleutian Islands. While it is not all too uncommon for nations to "innocently" pass within these limits, the US has been cautious in sailing its naval vessels within these Chinese claimed territories. The last time the US Navy navigated within the 12 mile limits was in 2012 near the Spratlys.
In the coming months it will be compelling to see if the US continues to test China's claims. Some US security officials believe these exercises will have to be a common occurrence in order to be effective. This maneuver gives China the last clear chance in responding to US actions. So far, China has responded through diplomatic channels, the media, and shadowing the US patrol. The potential for escalation is here. But the question remains how valuable are these islands and perhaps more importantly, China's claims and legitimacy in the face of an almost $2 billion dollar destroyer.