The region's smaller states sought American support. But the U.S. remained careful not to be drawn into the competing claims over sovereignty, some of which are tenuous, while on others China sometimes has a stronger legal position. Moreover, the U.S. had to focus on larger issues in its relationship with China.
This began to change when China initiated an active policy of dredging sand to fill in reefs and build islands in at least five locations. Earlier this year, analysts released images of what is expected to be a 10,000-foot (3,000-meter) runway on Fiery Cross Reef.
The U.S. argues that UNCLOS grants foreign ships and planes free access beyond a 12-mile territorial limit, while China claims that military flights cannot cross its 200-mile economic zone without its permission. If China claimed such a zone for each of the sites it occupies, it could close off most of the South China Sea. As one U.S. official put it, China seems to be trying to "create facts on the ground" -- what Admiral Harry Harris, the U.S. commander in the Pacific, calls a new "great wall of sand."
China correctly declared that it was within its sovereign rights to dredge, and that it was merely following the lead of its neighbors, whose governments had also been creating structures to bolster their claims. But American suspicions were heightened by the fact that in 2013, in a separate dispute between China and Japan over the Senkaku/Daiyou Islands in the East China Sea, the Chinese government unilaterally declared an Air Defense Identification Zone without prior warning. The U.S. response was to fly two B-52 bombers through the unrecognized zone. This set a precedent for the recent naval reconnaissance flight (which had a team of CNN reporters on board).
The U.S. response was designed to prevent China from creating a fait accompli that could close off large parts of the South China Sea. Nevertheless, the original policy of not becoming embroiled in the sovereignty dispute continues to make sense. The irony is that the U.S. Senate's failure to ratify UNCLOS means that the U.S. cannot take China to ITLOS over its efforts to convert reefs into islands and claim exclusion zones that could interfere with the right of free passage -- a major U.S. interest.
But, because China has ratified UNCLOS and the U.S. respects it as customary international law, there is a basis for serious direct negotiation over clarification of the ambiguous nine-dashed line and the preservation of freedom of the seas. With properly managed diplomacy, a U.S.-China conflict in the South China Sea can and should be avoided.