Ambiguous provisions and changing geopolitical realities make the case for review of the 1951 Philippines-U.S. Mutual Defense Treaty (MDT). The treaty has been the bedrock of the bilateral alliance, and has long benefited both sides. It allowed the U.S. military access to the strategic archipelago following independence in 1946, while enabling the Philippines to focus on internal security in its early years. However, China’s aggressive footprint in the West Philippine Sea (the portion of the South China Sea adjacent to the Philippines) has grown, casting doubt on the treaty’s deterrent effects, and the more inward-looking and transactional U.S. leadership of President Donald Trump raises questions about the continued relevance of the MDT in its present form.

In late December 2018, Philippine defense secretary Delfin Lorenzana ordered a review of the 67-year old treaty, with the objective of either maintaining, strengthening, or scrapping it. The review, especially if it were to result in an abrogation of the treaty, has far reaching consequences for subsequent bilateral security arrangements. This includes the 1999 Visiting Forces Agreement, which facilitates annual joint military exercises, and the 2014 Enhanced Defense Cooperation Agreement, which allows U.S. military rotational presence and access to several Philippine bases in the country. Lorenzana also called for the review of the pre-independence 1935 National Defense Act. The move may have caught observers by surprise, coming barely two weeks after the successful repatriation of the Balangiga bells. While the bells’ return may have emboldened Manila to push more firmly for U.S. commitment at this time, the roots of the issue stretch back decades.

There are four salient issues that will crop up in the review of the MDT. These are the treaty’s scope, the activation process (i.e., what actions would trigger the treaty), capacity to respond to actions below the threshold of armed attack, and whether a more comprehensive system of regional security should replace this arrangement.

With a front-line seat on the South China Sea and its multi-party territorial and maritime disputes, it is no wonder the Philippines wants clarity on the treaty’s geographic scope—that is to say, whether islets in the South China Sea even fall under the protection of the MDT. Since the 1970s, Manila has occupied one of the largest natural land features in the sea. Pag-Asa (Thitu) Island, home of the Philippines’ lone airstrip in the South China Sea and nominal capital of the Kalayaan Island Group, is the Philippines’ smallest municipality. It sees as a double standard Washington’s readiness to confirm the U.S.-Japan MDT’s applicability to the Senkaku Islands dispute, while remaining ambiguous on whether Manila can expect the same in the Kalayaans.  Hence, while the United States’ policy of not taking sides in the disputes is understandable—ambiguity is valuable for the flexibility it provides both parties—its reluctance has led to disappointment. Security analysts now fear that continued trepidation could invite adventurism from third parties.

The absence of a provision that automatically triggers the treaty in times of serious contingency means that one side is left at the mercy of the constitutional processes of its supposed ally. To this point, the unhealthy executive-legislative relations observed in Washington during recent administrations, as well as an executive who publicly supports downscaling of perceived “unjustified” and overstretched foreign commitments, has prompted significant concern in Manila.

Likewise, maritime agencies increasingly face assertive actions that fall short of “armed attack” as laid out in Articles IV and V, and are perplexed by how to respond appropriately. Such “gray zone tactics,” including use of water cannons or dangerous and unprofessional maneuvers by other vessels or aircraft, create an array of scenarios where agencies are threatened outside the lines of a traditional “armed attack”. Expanding the definition of armed attack or adopting a new term to encompass such gray zone tactics may help reinvigorate the MDT’s deterrence value.

An effective, inclusive security arrangement has long eluded the region. As great power rivalry intensifies, the difficulty of reconciling expanded economic engagement with China and robust security ties with the United States creates a serious dilemma for Manila. This quandary has only worsened, since the Duterte administration launched its reset of ties with Beijing and ASEAN nations have continued their efforts to manage the disputes at bilateral and regional levels. The new reality is a world away from the Cold War context under which the treaty was signed, underscoring the need for a serious rethink. America’s postwar hub-and-spokes system, based on a series of security treaties it signed with East Asian and Pacific countries like the Philippines, long undergirded regional security in a unipolar world order. But the shifting nature of geopolitics now, to some, shows the collective self-defense network as a tool to constrain China’s resurgence. The contest becomes apparent in the competing security visions put forward by the key protagonists— China’s New Asian Security Concept and U.S.’ Free and Open Indo-Pacific. The obvious geopolitical agenda behind these contrasting visions dampened enthusiasm from regional states, not least the Philippines. For Manila, the potential fallout from the use of Philippine bases for U.S. surveillance sorties or freedom of navigation operations in the South China Sea is a cause for deep concern.

President Duterte and Defense Secretary Lorenzana seem to be playing the China and U.S. cards in tandem, with the former developing closer ties with Beijing as the latter tends to the alliance with Washington. This gives shape to the administration’s avowed independent foreign policy. Lorenzana calling for a review of the MDT therefore raises concerns over the balance of that foreign policy. The timing could also be ominous for the alliance. Goodwill visits from the Russian and Chinese navies opened the year’s military diplomacy. Sri Lankan president Maithripala Sirisena, a key supporter of China’s Maritime Silk Road in the Indian Ocean, also became the first foreign leader to visit the country in 2019. Are these coincidences, or clear signals to Washington ahead of a potential state visit by Duterte where the fate of the alliance can be tabled?

The MDT review may be disruptive, but the treaty’s ambiguity and evolving geopolitical realities have clearly outweighed institutional inertia in the initiation of the process. The rise of unconventional leaders like Presidents Duterte and Trump, who dare to challenge the conventional understanding of their countries’ fundamental interests, adds a novel twist and may determine the treaty’s future.

About Lucio Blanco Pitlo III

Lucio Blanco Pitlo III is a Research Fellow at the Asia-Pacific Pathways to Progress Foundation, Lecturer at the School of Social Sciences at Ateneo de Manila University and Contributing Editor (Reviews) for the Asian Politics & Policy Journal. His research interests include Southeast Asia in great power interaction, maritime and energy security, and China’s Belt and Road initiative.