How China Is Trying to Dominate and Control the South China Sea Why tensions are spiking: China has for many years now been building new island-like structures, adding airstrips, and placing weapons in and around highly disputed areas of the South China Sea. The Pentagon’s long-standing opposition to Chinese phony island-building, or “land reclamation,” in the South China Sea is based upon the definition of “island” as it is explained in the U.N. Convention Law of the Sea, an international agreement negotiated in the 1980s and updated in the 1990s. China has for many years now been building new island-like structures, adding airstrips, and placing weapons in and around highly disputed areas of the South China Sea.