The Award in the Philippines v. China arbitration case may have several major implications for the United States’ role in the region.
First, having positioned itself as an advocate of international law and a rules-based international order, the Award may embolden US policymakers in their efforts to securitize maritime areas in the region. In particular, the conclusions outlined in the Award may be used as justifications for US freedom of navigation operations in the South China Sea, despite the fact that the US has yet to ratify the United Nations Convention on the Law of the Sea (UNCLOS).
Second, in the event of military escalation between the Philippines and China or other rival claimants, US policymakers will have to carefully consider the country’s obligations to its ally, the Philippines, under the Mutual Defense Treaty (MDT) of August 30, 1951; the Visiting Forces Agreement and Counterpart Agreement that came into force on May 27, 1999; and the Enhanced Defense Cooperation Agreement (EDCA) signed on April 28, 2014. Because of the content of the Award, the US may be under greater pressure to intervene on behalf of the Philippines if any military incidents involving it occur.
Third, the US, despite its political rhetoric of impartiality, has placed itself on the side of the Philippines and several other littoral states through its support for the arbitration case. As a result, it has sided against China and, to some extent, Taiwan in terms of the legality of their claims and the means of dispute settlement. With international law lacking any means of enforcement, the US may feel compelled to act as the hammer of justice in the region, a role that it is – for better or for worse – already quite familiar with.