Updated at 12:01 p.m. ET on 2014-2-10
The United States for the first time has explicitly rejected the U-shaped, nine-dash line that China uses to assert sovereignty over nearly the whole South China Sea, experts say, strengthening the position of rival claimants and setting the stage for what could be an international legal showdown with Beijing.
Washington has always said that it takes no position on competing territorial claims in the South China Sea among China, the Philippines, Vietnam, Malaysia, Taiwan, and Brunei and opposes any use of force to resolve such issues.
But U.S. Assistant Secretary of State for East Asian and Pacific Affairs Daniel Russel in effect ended the ambiguity last week when he testified before the House of Representatives Committee on Foreign Affairs, experts say.
Russel said that under international law, maritime claims in the South China Sea "must be derived from land features" and that any use of the nine-dash line by China to claim maritime rights not based on claimed land areas "would be inconsistent with international law."
The international community, he said, would welcome China to clarify or adjust its nine-dash line claim to bring it in accordance with the international law of the sea.
"I think it is imperative that we be clear about what we mean when the United States says that we take no position on competing claims to sovereignty over disputed land features" in the region, Russel said.
Unlike other countries, Beijing's claim to up to about 90 percent of the South China Sea is not based on claims to particular islands or other features but on a historical map China officially submitted to the United Nations in 2009.
The map contains a nine-dash line forming a U-shape down the east coast of Vietnam to just north of Indonesia and then continuing northwards up the west coast of the Philippines.
The nine-dash line has been considered by many experts as incompatible with the 1982 United Nations Convention on the Law of the Sea (UNCLOS), which rejects historically based claims.
Jeffrey Bader, once U.S. President Barack Obama's chief advisor on China, referred to Russel's testimony and said that "for the first time, the United States government has come out publicly with an explicit statement that the so-called 'nine-dash line' ... is contrary to international law."
"By explicitly rejecting the nine-dash line, Assistant Secretary Russel and the administration have drawn our own line in the right place," Bader, now a senior expert at Washington-based Brookings Institution, said in a report.
Washington had made clear that its objection is a "principled one, based on international law, not a mere rejection of a claim simply because it is China’s," he said.
Russel's statement was immediately dismissed by Beijing, which has grown increasingly aggressive in asserting its territorial claims in the region, fueling tensions in waters important for fishing, shipping, and oil exploration.
"Some U.S. officials make groundless accusations against China," Chinese foreign ministry spokesman Hong Lei said.
The nine-dash line, he said, was established way back in 1948, a year before the establishment of the People’s Republic of China, and had been “supported by successive Chinese governments.”
Washington's public rejection of the nine-dash line "is a semi-big deal," said Julian Ku, a law professor at New York-based Hofstra University.
It "shows how the U.S. is going to use international law as a sword to challenge China’s actions in this region," he said on Opinio Juris, an online forum for informed discussion and lively debate about international law and international relations.
He expressed surprise that the U.S. government has never actually publicly stated such an argument before.
Russel's statement "fits comfortably within the U.S. government’s long-standing positions on the nature of maritime territorial claims."
Washington has always been a little unclear whether it has been neutral on the nine-dash line but Russel ended the ambiguity, Ku said.
Bader said the U.S. government should make clear to the other South China Sea claimants, and to Southeast Asian countries like Singapore and Thailand, that Washington expect them to be public in their rejection of the nine-dash line under international law.
"The U.S. should ensure that its approach is not seen as unilateral," he said. "It is not, but sometimes other countries are publicly quiet but privately supportive."
The U.S. move also offers a "legal roadmap" for other countries that are not claimants in the region, Ku said.
"It is hardly a controversial legal position, and should be fairly easy for the EU, Canada, or Australia to adopt," assuming they don’t mind annoying China, Ku said.
China's nine-dash line claim is already under challenge by the Philippines in the United Nations.
Manila had brought the case up a year ago under the UNCLOS, saying the nine-dash line has no basis under the law.
UNCLOS states that coastal states such as the Philippines are entitled to a territorial sea extending 12 nautical miles as well as a 200-mile economic exclusion zone in which they have rights to fish and extract undersea resources.
It's the first time that Beijing has been challenged under the convention, ratified by more than 160 countries—including China and the other claimants in the South China Sea but not the United States, where some senators are concerned it would limit commerce and allow international bodies to wield greater control over U.S. interests.
In 2012, China took control of a disputed and potentially strategic reef—the Scarborough Shoal—in the South China Sea that had been under Philippine jurisdiction.
Washington's rejection of the nine-dash line came after President Benigno Aquino sought the support of the international community in resisting China’s territorial claims and ahead of U.S. President Barack Obama's upcoming visit to Japan, Malaysia, and the Philippines as part of an effort to make up for a canceled visit to the region last year.
“If we say yes to something we believe is wrong now, what guarantee is there that the wrong will not be further exacerbated down the line?” Aquino said in an interview with The New York Times. “At what point do you say, ‘Enough is enough?' Well, the world has to say it.”
Air defense zone
Beijing's increasing assertiveness in defending its territorial claims in the region has also been reflected by its recent declaration of an air defense identification zone (ADIZ) over disputed islands controlled by Japan in the East China Sea, and its new rules to regulate fishing in a huge tranche of the South China Sea.
Speculations have been rife that Beijing would also impose an ADIZ in the South China Sea with Washington warning that any such move could lead the U.S. military to change its posture in the region.
“We oppose China’s establishment of an ADIZ in other areas, including the South China Sea,” Evan Medeiros, senior director for Asian affairs at the National Security Council, told Japan's Kyodo news agency about a week ago.
“We have been very clear with the Chinese that we would see that (the setting of another ADIZ) as a provocative and destabilizing development that would result in changes in our presence and military posture in the region,” Medeiros said.