China's argument with the U.S. over interpretation of UNCLOS is an example of how states can mold customary international law in ways inimical to U.S. interests

One way to interpret the challenges emanating from the PRC is that Beijing resents a legal regime that appears to favor American security at the PRC’s expense. Unable to change the words of UNCLOS, the PRC argues—laboriously, at times—to persuade the United States that the spirit of the law clearly supports Beijing’s interpretation, even where the word of the law may be insufficiently precise.

Hence, Chinese and American analysts of UNCLOS dicker about the meaning of article 58(3), which reads: “In exercising their rights and performing their duties under this Convention in the exclusive economic zone, States shall have due regard to the rights and duties of the coastal State and shall comply with the laws and regulations adopted by the coastal State in accordance with the provisions of this Convention and other rules of international law in so far as they are not incompatible with this Part.”¹⁶ PRC analysts point to the “due regard” clause as evidence of the obligation of foreign states to abide the laws of coastal states and the right of coastal states to restrict military activities in the EEZs off their coasts. American analysts tend to view this conclusion as smuggling into the article a privilege that was explicitly rejected by the drafters of the convention.

It is conceivable, of course, that advocates writing on behalf of the PRC offer interpre- tations of UNCLOS that are in fact meant to reopen and extend negotiations about issues that have, apparently, been settled. By challenging the understanding of what is permissible in the EEZ, the Chinese analysts may be hoping that other states will follow suit, adjusting what would then be seen as customary international law and hoping that the legal justifications they offer will likewise become the new norm. This, indeed, is precisely why some American proponents of UNCLOS argue that the United States must ratify the convention. For example, Rear Adm. Arthur E. Brooks, commander of the Seventeenth Coast Guard District, has said, “While reliance upon customary interna- tional law has served us well for many years, it does not adequately protect our interests. Customary international law is based on the evolving practice of States; it can and does erode over time. The Law of the Sea Convention provides the legal certainty and stabil- ity” that the admiral believes would assure U.S. interests for the long term.¹⁷