> I find it troubling you present the context improperly yourself (China v. UNCLOS)

Disputes are fractal. Any summary will be incomplete to some observer.

The United Nations Convention on the Law of the Sea, to which China is a party (but the United States is not) [1], ruled with the Philippines on the South China Sea's territoriality being drawn by UNCLOS rules. Others in the region disputing China's claims take similar positions [2]. The UUV was seized closer to the Philippine shore than to mainland China.

[1] https://en.wikipedia.org/wiki/United_Nations_Convention_on_t...

[2] http://timesofindia.indiatimes.com/india/India-and-Indonesia...