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On Friday Secretary of State Hillary Rodham Clinton announced that the peaceful resolution of competing sovereignty claims to the South China Sea is a U.S. "national interest." "The U.S. supports a collaborative diplomatic process by all claimants for resolving the various territorial disputes without coercion," she said in Hanoi during a regional security conference, the Asean Regional Forum. "We oppose the use or threat of force by any claimant."

Beijing quickly reacted. Foreign Minister Yang Jiechi characterized Clinton's comments as "an attack on China," and in a sense he was right. China has claimed virtually all that body of water as its own. By doing so, Beijing has said it has sovereignty over the continental shelves of the Philippines, Brunei, Malaysia,...