During a media interview on the sidelines of the Kadiwa ang Pasko Caravan in Quezon City, President Ferdinand Marcos, Jr. said: “The Mutual Defense Treaty (MDT) is continuously under negotiation and evolution. I always call it an evolution because things are changing.” The President added that the “defense pact between the two countries is under review because the US has “many requests and proposals,” particularly in the implementation of the 2014 Enhanced Defense Cooperation Agreement (EDCA). He also revealed that the MDT review was one of the topics discussed with US Vice-President Kamala Harris, who made an official visit to the Philippines in November 2022.
The President added: “Yes, we covered that (the MDT) and many more subjects. But essentially, on security, we are looking at the things they are proposing, the joint exercises, the EDCA, the use of our bases, all of these. We are in the middle of that.”
President Marcos’ observation about the MDT’s evolution reflects his profound understanding of the legal basis of the Philippine-US alliance. When the MDT was signed in 1950, the agreement simply provided a venue where the two allies could consult each other in case of an armed attack against any of the parties. From a mere supplementary treaty to the 1947 Military Bases Agreement (MBA), it became the cornerstone of the two countries’ security relationship.
During the Cold War, American air and naval forces based in the Philippines were available and capable of dealing with regional crises. They would be committed to the host country’s territorial defense and the protection of American interests in the West Pacific in the event of a general conflict. The presence of American forces in the Philippine military bases, rather than the MDT, was deemed essential to back US security guarantees to the host country and to ensure its strategic posture in Southeast Asia.
However, the withdrawal of American forces in 1992 transformed the 1951 MDT into a mere piece of paper. Nonetheless, Manila and Washington kept the MDT in force without any amendment. Both sides agreed to convene the Mutual Defense Board (MDB) every three months as an effective mechanism for consultation on mutual security concerns. In November 1992, the MDB approved the continued conduct of joint military training, such as the annual Balikatan (should-to-shoulder) exercises. It also proposed routine visits of American ships, aircraft transits, and continued assistance by US forces to Filipinos during natural disasters and calamities.
To facilitate the military exercises and port visits, the Philippines and the US signed the Visiting Forces Agreement (VFA) in 1998, which the Philippine Senate ratified in 1999. The 1999 VFA refers to a Status of Forces Agreement (SOFA) that provides the legal regulatory framework for treating American military and civilian personnel visiting the Philippines for joint military exercises and other matters.
THE WEST PHILIPPINE SEA DISPUTE AND THE MDTDuring his six-year term, the late Philippine President Benigno Aquino III sought American naval and air support for Philippine forces in the Spratlys based on the MDT. Philippine defense and foreign affairs officials argued that an armed attack on Philippine metropolitan territory and forces anywhere in the Pacific, including the South China Sea, should trigger an automatic US armed response.
Then US Secretary of State Hillary Clinton upheld the US defense commitment to the Philippines amid the rising tensions between Manila and Beijing over the disputed Spratlys. She, however, could not categorically tell what the US would do if China attacked a Philippine ship or aircraft in the South China Sea. The American position on an act of armed aggression had been ambiguous, to say the least.
In December 2018, then Department of National Defense Secretary Delfin Lorenzana announced in a press briefing the review of the 1951 Philippine-US Mutual Defense Treaty by the Department of National Defense (DND). He stated that the time has arrived for the MDT “to be revisited, given that its provisions were formulated in the early 1950s.” The call for the MDT review stemmed from Secretary Lorenzana and the defense establishment’s apprehension that the Philippines might be dragged into an armed confrontation between the US and China.
During his March 2019 visit to Manila, then Secretary of State Michael Pompeo declared: “As the South China Sea is part of the Pacific; any armed attack on Philippine forces, aircraft, or public vessels in the South China Sea will trigger mutual defense obligations under Article IV of our mutual defense treaty.” His comment was aimed to reassure the Philippines that the US would support its ally relative to the Chinese construction and militarization of artificial islands in the South China Sea.
THE MDT’S CONTINUING EVOLUTIONIn September 2021, the two allies commemorated the 70th anniversary of their formal treaty alliance. By then, both allies found it necessary to sort out and maximize the effectiveness and relevance of their alliance by applying the Goldilocks Principle — neither too hot, nor too cold — in their security relationship with the US, concretizing its mutual defense obligations to the Philippines; while both countries are committing themselves together to act cautiously, reliably, and responsibly amidst China’s aggressive behavior and maritime expansion in the South China Sea.
This approach is apparent in the Nov. 16, 2022, “Joint Vision for a 21st Century United States-Philippines Partnership.” The joint declaration provides for the two allies to strengthen their combined capabilities and to develop new bilateral defense guidelines that will buttress their common understanding of their respective roles, missions, and capabilities under the MDT. On the other hand, it commits the Philippines and the US to further diplomatic efforts in building an international coalition that will support an international law-based maritime order.
Dr. Renato De Castro is a Trustee and Convenor of the National Security and East Asian Affairs Program of the Stratbase ADR Institute.