US Philippines Defence Pact at 75: Can the Alliance Sustain Its New Momentum?

A treaty alliance enters its 75th year

The Philippines and the United States have renewed plans for military exercises, maritime cooperation and specialist exchanges as they mark 75 years of their Mutual Defense Treaty. The anniversary comes as pressure rises in the South China Sea and Washington and Manila seek to make their security relationship more capable, more regular and more useful in a crisis.

Admiral Samuel Paparo, commander of US Pacific Command, and General Antonio Nafarrete, chief of staff of the Armed Forces of the Philippines, co chaired the annual Mutual Defense Board Security Engagement Board meeting at Camp Aguinaldo in Quezon City on August 7, 2026. They signed an eight star memorandum approving guidance and a schedule of activities for the next year.

The approved program includes large military exercises, professional exchanges and cooperation covering maritime security, humanitarian assistance and disaster response. It builds on a relationship that has generated hundreds of military activities each year and places regular contact between the two forces at the center of the alliance.

The treaty, signed on August 30, 1951, commits both countries to respond to common dangers if either side faces an armed attack on its armed forces, public vessels or aircraft in the Pacific. It does not create an automatic declaration of war. Any response would still be shaped by each country’s laws and political decisions, a distinction that has mattered as encounters at sea become more frequent.

Why maritime security has become the main test

The alliance now operates in a much more contested setting than it did when the treaty was signed. Manila has repeatedly reported confrontations and dangerous encounters with Chinese vessels in waters within the Philippines’ exclusive economic zone, particularly around disputed areas in the West Philippine Sea. China rejects the 2016 international arbitral ruling that rejected its expansive claims in the South China Sea.

For the Philippines, the issue is tied to sovereign rights, fishing grounds, energy resources and the safety of its coast guard and navy. For Washington, the area is part of a wider effort to preserve freedom of navigation and prevent coercion from changing the regional balance. US officials have repeatedly stated that treaty commitments cover attacks on Philippine public vessels, including coast guard ships, in the South China Sea.

That position is designed to deter an attack while leaving room for diplomacy. It also creates a difficult calculation. A collision, water cannon incident or other confrontation may be serious without meeting the treaty’s threshold for an armed attack. The two governments therefore need reliable communication, shared information and a common understanding of how a crisis would be managed.

During a meeting in Singapore in May, Philippine Defense Secretary Gilberto Teodoro Jr. and US Secretary of War Pete Hegseth described the alliance as ironclad. Washington also renewed the Communications Interoperability and Security Memorandum of Agreement for 15 years, supporting secure communications, information sharing and cyber cooperation.

From annual drills to a wider military network

The strongest visible sign of the alliance’s expansion is Exercise Balikatan. The 2026 edition ran from April 20 to May 8 and involved about 17,000 troops from the Philippines, the United States, Australia, Japan, Canada, France and New Zealand. It was the largest and most expansive version of the exercise, moving beyond a traditional bilateral drill toward a multinational rehearsal for the defense of the Philippines.

The exercise covered air and missile defense, maritime security, live fire activity and operations across several areas, from Luzon to Mindanao. Such training helps military units work with different command systems, communications equipment and operating procedures. It also gives partner countries a better picture of how they might support the Philippines during a natural disaster or a security emergency.

Japan, Australia and New Zealand have become frequent participants in exercises with Manila and Washington. South Korea, France, Canada and other partners are also taking part in selected activities. This network gives the Philippines more options and shows that maritime security is being treated as a shared regional concern rather than a matter between Manila and Beijing alone.

Still, larger exercises do not by themselves guarantee a unified response in wartime. Political consent, logistics, intelligence sharing and the ability to sustain operations would all shape what partners could actually do. The annual schedule approved by the two military chiefs is meant to build those habits before a crisis occurs.

How the alliance is being modernized

The treaty is supported by several arrangements that give the relationship practical reach. The Enhanced Defense Cooperation Agreement allows expanded rotational access for US forces at agreed Philippine military facilities. It does not establish permanent US bases, a distinction that remains significant in a country where foreign military presence has long been politically sensitive.

The 1998 Visiting Forces Agreement provides the legal framework for many US military activities in the Philippines. The communications agreement renewed in Singapore supports secure links and cyber work. Together, these arrangements help turn a broad treaty promise into regular training, equipment support and operational planning.

Washington is also supporting infrastructure and Philippine military modernization. US officials have pointed to co investment in resilient facilities, advanced training and the use of EDCA sites. Four US Fast Response Cutters are being rotationally deployed to work with the Philippine Coast Guard on patrols and protection of the country’s exclusive economic zone.

The Philippines is seeking stronger maritime surveillance, air defense, naval capacity and coast guard capability. These assets are intended to help Manila monitor its waters and respond to pressure without relying on immediate US intervention. Better Philippine capacity also makes the alliance more credible from Washington’s perspective.

Washington stresses shared responsibility

US Undersecretary of Defense for Policy Elbridge Colby described the Philippines as a model ally during a forum in Manila. He said the alliance was undergoing a historic modernization and argued that durable partnerships require both sides to invest in their own security.

Colby also said Washington was seeking partners rather than protectorates. His message reflects a broader US demand that allies spend more on defense, improve readiness and take greater responsibility for their own territory. For Manila, the message brings support and resources, while also placing pressure on the Philippines to speed up procurement and institutional reform.

Before quoting Colby, it is useful to distinguish this approach from a promise of unlimited US protection. American officials are offering stronger deterrence and support, yet they are also asking the Philippines to build forces that can monitor and defend its own waters.

When our partners are strong, deterrence is strong. And that is exactly what we have here in Manila under the leadership of President Marcos, Defense Secretary Gilbert Teodoro, and other key leaders.

Colby said the United States was not leaving Asia and was instead pursuing a more focused, resource backed regional strategy. He linked the alliance to a wider effort to maintain a favorable balance of power along the first island chain, which stretches from Japan through Taiwan and the Philippines toward Southeast Asia.

Why questions about US commitment persist

Repeated American assurances have strengthened confidence in Manila, yet doubts about long term commitment have not disappeared. Philippine leaders must consider whether Washington would accept the cost of a direct confrontation with China, especially if an incident remained below the threshold of open war.

US elections and changing administrations add another layer of uncertainty. A government may support the treaty while placing different weight on alliances, regional deployments or competition with China. Philippine officials therefore want statements from Washington to be matched by equipment, infrastructure, exercises and planning that can survive political change.

The US position has been reinforced across several levels. Secretary of State Marco Rubio described the defense commitment as unwavering in a message for Philippine Independence Day. Hegseth praised Balikatan and backed US assistance for monitoring the Philippine exclusive economic zone. Colby visited Manila to discuss modernization and deterrence. Bipartisan US senators Pete Ricketts and Chris Coons also introduced a resolution supporting the alliance and opposing Chinese pressure in the South China Sea.

These steps show broad political and military support in Washington, although official declarations cannot settle every question about a crisis. The credibility of the treaty will depend on whether both governments maintain readiness, communicate precisely and act consistently when confronted with coercion.

Manila wants autonomy as well as alliance support

Philippine President Ferdinand Marcos Jr. has expanded defense cooperation with Washington while also building closer links with Japan, Australia, South Korea and other partners. This strategy gives Manila more sources of training, equipment and diplomatic support.

Japan has discussed transferring decommissioned Abukuma class destroyer escorts and TC 90 aircraft to the Philippines. Working groups are examining training, maintenance, information sharing and the long term management of the equipment. Australia is expanding defense cooperation, while Singapore is contributing to training and disaster response activities.

The Philippines also holds the chair of the Association of Southeast Asian Nations in 2026. Manila has used that position to present itself as a meeting point for regional partners, with attention to freedom of the seas, disaster relief and a rules based order. Its policy seeks to avoid dependence on a single power while keeping the US treaty at the center of national defense.

That balance can be difficult. Stronger US access may improve deterrence, while closer alignment can also make the Philippines more visible in US China competition. Manila’s leaders must manage domestic concerns about sovereignty and foreign troops alongside the need for outside support.

What the anniversary means for the region

The anniversary is less a ceremonial milestone than a review of how the alliance works in practice. The two countries are planning more exercises, improving secure communications, expanding access to facilities and linking their forces with a larger group of partners.

The arrangement also reaches beyond combat preparation. Humanitarian assistance and disaster response are central missions for both militaries, given the Philippines’ exposure to typhoons, earthquakes and volcanic activity. Regular cooperation can provide value to communities even when no military confrontation takes place.

For China, the expanded alliance network signals that pressure on the Philippines may bring a wider response. For Southeast Asian states, it presents both reassurance and a concern that sharper rivalry could narrow diplomatic space. The Philippines has sought to show that stronger defense ties can support its sovereignty without closing the door to regional dialogue.

At 75, the treaty is active and expanding, yet its strength will be judged by more than the number of troops at an exercise. It will rest on Philippine defense improvements, sustained US presence, allied coordination and the ability of leaders to prevent maritime incidents from becoming a wider conflict.

The Bottom Line

• The Philippines and the United States renewed defense cooperation on the 75th anniversary of their 1951 treaty.
• A new eight star memorandum approved exercises, military exchanges and work on maritime security and disaster response.
• Balikatan 2026 involved about 17,000 troops from seven countries.
• EDCA, the Visiting Forces Agreement and the renewed communications agreement support practical cooperation.
• Washington is promising stronger deterrence while asking Manila to invest more in its own defense.
• The alliance faces its main test in the South China Sea and in questions about US commitment during a crisis.