Use Maritime-Law Trends to Offset Beijing’s Gains in the South China Sea


Exploiting changes to the law of the sea can help put China in a place where it has bought much less than it bargained for.

It is sometimes said that China’s construction of man-made islands in the South China Sea resembles the growth of a forest: It expands slowly, but once it has arrived it is difficult to uproot. Yet the law of the sea is changing as well, in ways that might be used to offset Chinese gains.

At this writing, the Subi and Mischief reef installations boast naval bases, runways, hangars, air defenses and communications infrastructure—including jamming equipment. This circumstance presents a widely acknowledged security problem, complicated by overlapping national claims to the area. It is also a challenge to basic freedoms of navigation, since China has objected to U.S. Navy vessels’ innocent passage through what would be those islands’ territorial seas.

As part of their response, the United States and its security partners might take advantage of certain long-term trends in the law of the sea. One such strategy involves the changing nature of sovereignty as practiced by the world’s seagoing nations across various ocean jurisdictions, as I describe in a forthcoming article in the journal Oceans Development & International Law.

To illustrate these long-term trends, consider the Proliferation Security Initiative. Launched in 2004, the PSI was designed by the United States to help interdict WMDs transiting the world’s oceans. Since then, the PSI has grown to include over 100 participating states, each of which adopts a set of limited “interdiction principles.” Although somewhat open to interpretation, the principles imply that the participant nations reserve the right to board offending vessels wherever they are, including—and this is crucial—in the territorial seas of consenting coastal states, in contiguous zones, and during strait transit.

In this way, the PSI has served as the vehicle for a subtle but distinct change in how the international community administers navigational freedoms. Historically, international law has treated vessels as sovereign islands of their flag state. With few exceptions, only the exercise of port state jurisdiction, or some other territorially-based jurisdiction, could empower a state to board a ship. The PSI represents a shift in these age-old principles: increasingly, states treat a vessel’s individual behavior—like transporting WMDs—as the reason to board it or otherwise interfere with it.

The trend can be seen in the world’s merchant fleet, too. Flag states, and the countries regulating shipowners, have gradually extended their regulation of merchant vessels. As a result, far-flung regulators increasingly dictate what happens aboard vessels, regardless of whether the vessels are on the high seas, in innocent passage, or in a foreign port. Again, the trend is that a vessel’s behavior, rather than its geographic location, increasingly subjects it to a state’s jurisdiction.