Prof. Dindo Manhit, President at the Stratbase ADR Institute
Last week was remarkably eventful for those of us following developments in the South China Sea. Late last night (Manila time), the International Tribunal for the Law of the Sea announced that the tribunal had ruled that it has jurisdiction to hear the Philippine case on its merits.
(In this photo: legal counsels and representatives from the Philippines argue on the tribunal’s jurisdiction over the case against China on the South China Sea dispute. Image Source: Manila Bulletin)
The Philippine case is composed of 15 submissions, of which the tribunal found that it has jurisdiction over 7 and that it would reserve its consideration of jurisdiction on further 7 for the merits phase of the proceedings. The tribunal directed the Philippines to clarify and narrow the scope of one submission. The full release from the tribunal can be found online.
The announcement presents a very positive development for the Philippines, which had turned to the international tribunal in 2013 not long after Philippine and Chinese maritime vessels endured a stand-off over Scarborough Shoal in 2012. After both sides agreed to withdraw from the Shoal, Chinese maritime assets returned and prevented Filipino fishermen from pursuing their livelihoods there.
(Image Source: http://www.gla.ac.uk/)
In an interview earlier this month, Foreign Affairs Secretary Del Rosario told Foreign Policy magazine that “At the end of the day, we really think international law is the great equalizer.” 
In related news, the United States sent on Tuesday the USS Lassen to sail within a 12-mile radius of Subi Reef in the Spratly island group. Although Subi Reef is claimed by China, Malaysia, the Philippines, and Vietnam, the reef has been the site of extensive dredging and reclamation by China since 2012.
(Image Source: csis.org)
The reef had previously been above water only at low tide; today it hosts a four-story building with weather tracking and radar devices, a helipad, and 200 soldiers. Subi Reef is only 16 nautical miles (23 kilometers) from Philippine-held Pag-asa (international name Thitu) island. Within Manila, that’s comparable to the distance from the University of the Philippines-Diliman to Ninoy Aquino International Airport.
The United States routinely performs ‘operational assertions’ or ‘Freedom of Navigation operations,’ wherein its vessels sail through waters claimed by any given country in cases where the US considers these claims excessive and not in keeping with international law.
(The U.S. Navy’s Freedom of Navigation Program is an important expression of international law. Image Source: http://thediplomat.com/)
Although operational assertions worldwide are routine for the US Navy, this operation was the first from the United States in the contested area since 2012. By sailing within 12-mile radius of Subi Reef, the US Navy provided a physical demonstration of the United States’ legal opinion that the transformation of these reefs does not change their entitlements under international law (that is, that they do not generate even a 12-mile radius of coastal waters given to provided in the Law of the Sea Convention). Writing in Washington, experts from ADRI partner institution the Center for Strategic and International Studies (CSIS) explain the operational assertions. 
At ADRi in Manila, Philippines, we are watching for the reactions of China and our counterpart nations in Southeast Asia to both of these events. It is heartening to see preliminary returns on the Philippine effort to elevate the maritime disputes to the international court and that support for the rule of law is manifesting on the ground.
Looking forward, US officials have indicated to the press that the United States Pacific Command is working on a plan to conduct such operations into the Spratly island group from Clark Air Base . These future plans cannot be disentangled from the 2014 Enhanced Defense Cooperation Agreement (EDCA) between the Philippines and the United States, which is awaiting a final ruling from the Supreme Court. We are looking forward to a ruling on EDCA at the soonest possible time.