BOTH the Bush and Clinton administrations have acknowledged that conflicting claims to islands in the Spratly chain are a source of tension in East Asia that, in the worst case, could lead to regional instability.
Even so, the United States has adopted a hands-off policy, calling for restraint and urging regional efforts at conflict resolution. ''We take no position on the merits of the competing claims, and we believe they should be resolved peacefully,'' says a State Department official.
Diplomatic analysts attribute the US's reticence, in part, to the imminence of a leadership change in China.
''The US seems reluctant to challenge China's assertive behavior and its expansive claims to most of the South China Sea because it could strengthen the hand of the military in the run-up to the Chinese succession,'' says senior fellow Mark Valencia of the East-West Center in Honolulu.
Meanwhile, the Manila government has not invoked its 1952 mutual-defense treaty with the US in the wake of the recent Chinese encroachments on islands that lie within its 200-mile economic zone. Since the US takes no position on conflicting claims to the islands, the treaty would not come into effect in any case.
Concern over competition for the Spratlys runs higher at the Defense Department, where the issue is weighed in the context of an aggressive Chinese military buildup and more combative Chinese behavior in the South China Sea.
Both are being invoked by the Pentagon to bolster the case for maintaining a strong defense posture in the region in the face of budget cuts.
Last month, the Pentagon issued a document warning that freedom of navigation in sea lanes that run through the South China Sea is of strategic interest to the US. The document contains no threat but, according to one expert on Chinese military affairs, Chong-Pin Lin of the American Enterprise Institute in Washington, it is an example of ''deterrence by ambiguity.''
''Our strategic interest in maintaining the lines of communication linking Southeast Asia, Northeast Asia, and the Indian Ocean makes it essential that we resist any maritime claims beyond those permitted by the Law of the Sea convention,'' notes the document, ''United States Security Strategy for the East Asia/Pacific Region.''
The convention recognizes a 12-mile territorial limit and a 200-mile economic zone beyond the shoreline of coastal nations; areas of the ocean beyond which are considered part of the global commons. China's claim to the islands and to most of the South China Sea is based on the discovery and use of both ''from time immemorial,'' according to the Chinese government. The US, which has not ratified the Law of the Sea Convention, has not contested China's claim to either.