A Map of Conflicts in the South and East China Seas
From Thomas Wright's "Outlaw of the Sea":
In July 2010, at the ASEAN Regional Forum (ARF) in Hanoi, U.S. Secretary of State Hillary Clinton stated that the United States believes that all maritime territorial disputes in the South China Sea must be resolved multilaterally and in accordance with international law. It is a policy that she repeated at the deadlocked 2012 ARF in Cambodia. For its part, China objected to the "multilateralization" of maritime disputes then and continues to do so now. Beijing believes that it is more likely to make gains if it strikes individual bargains with weaker powers, including Manila and Hanoi. The other capitals realize this, which is why they welcomed Clinton's commitment to multilateralism.
A strong multilateral structure in Asia is a prerequisite to balancing Chinese assertiveness. The United States should not take sides in other countries' disputes, but it can and must insist upon a strong regional framework to ensure that a rising China does not destabilize the status quo. On this issue, the 34 senators who oppose the treaty are taking Beijing's side. They are speaking up for the bilateralism and unilateralism that will harm the U.S.-led regional order in the Asia-Pacific. No doubt, news of Ayotte and Portman's recent declarations was greeted warmly in Beijing. U.S. allies and strategic partners in South East Asia, meanwhile, will be even more doubtful of Washington's capacity to maintain its leadership role. It is strategic multilateralism in the Atlantic that helped the United States to win the twentieth century. Without concordant multilateralism in the Asia-Pacific, it will not fare so well in the twenty-first.