The Philippines, one of America’s longest-standing allies, has been the target of a prolonged—and escalating—campaign of harassment and attempted intimidation by China in recent years. That campaign has included attacks on Philippine vessels operating in Philippine and international waters by Chinese surface combatants, coast guard vessels, and “private” craft; increased incursions into Philippine airspace and harassment of Philippine aircraft by Chinese air force jets; and thinly veiled threats by Beijing aimed squarely at Manila.
As a consequence, the Philippines has rewritten its national defense strategy to focus on capabilities and training relevant to defending Philippine sovereignty from Chinese aggression. Further, the Philippine military is making significant investments to counter such a campaign. The Philippines is also, in the words of President Donald Trump, some of the most “prime real estate on Earth,” with a location in the Western Pacific that enables continuing American presence in the South China Sea and close proximity to Taiwan.
It is in the interest of both the United States and the Philippines to deepen their security cooperation, as it is decidedly not in the interest of Washington or Manila for China to become the hegemon of the Western Pacific, whether such hegemony comes from overt military aggression or through sustained pressure campaigns designed to undermine political stability. Consequently, Manila’s increased investment in its military and in acquiring the capabilities to operationalize its new national security strategy, serves the interests of both Washington and Manila. U.S. assistance to the Philippines through Foreign Military Financing and sales, and joint training and professional military education, even as it maintains or expands its security footprint in the Philippines, serves the interests of both countries as well.
In late 2024, The Heritage Foundation released the Backgrounder “Strengthening the U.S.–Philippine Alliance,” which praised Manila’s new approach to defense and called for the Philippines to increase its defense spending to meet the needs of its new national defense strategy. The Backgrounder also called for the United States to provide increased political, material, and financial support to the Philippines to enable Manila to better defend its sovereign interests.REF Indeed, American investment in infrastructure in the Philippines as part of the Enhanced Defense Cooperation Agreement (EDCA) is also an integral part of the U.S. Indo–Pacific strategy and must be prioritized.REF In 2025 growing political capital is available to deepen the bilateral relationship and strengthen capabilities to mutual benefit, and this Issue Brief identifies concrete steps to do so.
The Strategic Picture
The following observations describe the emerging security architecture in the Western Pacific.
The Chinese Pressure Campaign. The Marcos Administration in the Philippines has distinguished itself over the past two years in its principled stand for Philippine sovereignty against Chinese aggression in the West Philippine Sea. Last year, the China Coast Guard and the People’s Liberation Army Navy (PLAN) perpetrated a long list of offenses against Philippine sovereignty, including initiating altercations with Philippine servicemembers, resulting in serious injuries and conducting routine harassment of Philippine fishermen. Just last month, a PLAN warship collided with a China Coast Guard ship while chasing a Philippine vessel, highlighting the dangerous and un-seamanlike behavior of both. Bizarrely—but unsurprisingly—China blamed the Philippines for the incident.
The Comprehensive Archipelagic Defense Concept (CADC). One of the ways Manila has responded to this sort of pressure is by rewriting its national defense strategy. Traditionally the Armed Forces of the Philippines have focused on internal counterinsurgency operations. In recent years, Philippine policymakers recognized that the threat picture for Manila had changed, requiring a new strategy. The CADC refocuses the Philippine Armed Forces on external threats and calls for a shift in procurement, training, and force posture to littoral combat operations, maritime operations, air defense, and asymmetric warfare.
Investments to Realize the CADC. It is not likely that Washington will ask the Philippines to increase its defense budget to 3.5 percent as Washington has done with other allies, since American policymakers recognize the different economic circumstances between the Philippines and allies like Australia and Japan. However, the Philippines will likely need to increase defense spending to realize its plans for the CADC. Philippine policymakers should start from a military planning perspective, identify what is needed to make the CADC work, and spend what they need to field the military capabilities required to operationalize and make credible the CADC.
Some recent investments by the Philippines are already moving in this new direction. In 2025 the Philippines accepted delivery of two corvettes from South Korea as part of the shift into more maritime operations.REF Last year, the Philippines also accepted a delivery of BrahMos anti-ship missiles from India, a necessary investment to deter and, if necessary, defeat hostile naval activity in the West Philippine Sea. Purchasing a mix of high-end capabilities (such as corvettes) and low-end capabilities (such as anti-ship missiles) represents a wise investment strategy. The best procurement strategy for the Philippines is just this sort of high-low mix, with a small number of high-end platforms that are especially useful for gray zone deterrence and a much larger number of cheaper asymmetric capabilities to offset the Chinese advantages in conventional capacity and quality.
Investments in short-range air defense (SHORAD), drones for intelligence, surveillance, and reconnaissance (ISR), and anti-ship missiles are all critically important for Philippine asymmetric capabilities to deter aggression in the West Philippine Sea. Ideally, many of these systems could be produced in the Philippines itself, which would lower the cost of purchasing the systems, build up the Philippine defense industrial base and expand defense innovation expertise, and provide an economic benefit to ordinary Filipinos.
How the U.S. Can Help
It is very much in the national interest of the United States for the Philippines to have a military capable of defending Philippine sovereignty. To that end, there are a number of areas in which the U.S. could help the Philippines to build such capabilities.
EDCA Infrastructure Building. The EDCA sites at Philippine military bases, such as Basa Air Base, Fort Magsaysay, Antonio Bautista Air Base, Mactan-Benito Ebuen Air Base, and Lumbia Air Base, are among the most important components of the U.S.–Philippine alliance. The improvements at these sites include command-and-control infrastructure, fuel storage, runway improvement, humanitarian assistance and disaster relief storage, urban combat facilities, ammunition storage, and new airport terminals, which are critical investments from the perspectives of both sides. The faster the infrastructure on these bases is completed, the better the Philippine military will be postured to deter Chinese aggression. From a U.S.–Indo–Pacific strategy perspective, in particular, it is absolutely vital that these projects be completed no later than 2026. This will require expedited timelines and more financial investment from the American side.
Professional Military Education. There is significant appetite in Manila for more American professional military education and joint training—particularly when it comes to the operational art of air and sea denial. Given that it is squarely within the U.S. interest to bolster the Philippines’ capability to defend the sovereignty of its airspace and waters from Chinese incursion, the U.S. should host more Philippine officers at U.S. war colleges and should also send officers to teach in the Philippines. A small number of American field-grade officers could be posted to the Philippines to teach doctrine and operational art relevant to the CADC, such as air defense operations and littoral combat.
Joint Training. Philippine soldiers are highly experienced in jungle warfare, due to their decades of real-world counterinsurgency operations. Conducting joint training in jungle warfare with American and Philippine troops would not only strengthen ties between the two militaries but would also provide direct operational benefit to American ground forces that have not operated in jungle environments in decades.
Coproduction. The United States should assist the Philippines as it seeks to develop a new small and inexpensive gunboat. Such assistance could take the form of the Philippines coproducing U.S.-designed gunboats, for example, or cheap drone systems in a deal similar to the one the United States recently agreed to with Taiwan. The Philippines has the ability to produce these sorts of systems, and the United States can provide crucial assistance with the design.
Assistance with Doctrine. The new Philippine national defense strategy will need to be backed up by doctrine in several areas that are relatively new to the Philippine Armed Forces—and are more familiar to U.S. defense officials and officers. The U.S. Marine Corps, in particular, could be very helpful in helping Philippine planners to articulate the role of the Philippine Army in littoral combat operations and anti-access/area denial, for example. The Australian Army could also play an important role, as Australia’s military is likewise engaged in a strategic pivot away from counterinsurgency and toward littoral combat operations.
Foreign Military Sales and Foreign Military Financing. Along with Taiwan and the United States’ other Indo–Pacific allies and partners that are crucial to deterring China in the Indo–Pacific, the United States should prioritize the Philippines for Foreign Military Sales and Foreign Military Financing. The United States should consider providing new systems that would make sense within a Philippine context. One additional system to consider providing is the Harpoon missile.
Domain Awareness. The Philippines needs increased capabilities for its own domain awareness, but in the meantime would greatly benefit from increased domain awareness sharing from the United States, especially in light of the aggressive air and maritime coercion campaign being conducted by Chinese forces against the Philippines that includes frequent territorial incursions.
Conclusion
The U.S.–Philippine alliance—like many alliances—has had its share of strong and weak points, where the capitals have drifted closer and farther from one another. The alliance is entering a period of what is likely to be sustained close cooperation. Manila recognizes that Beijing treats its neighbors with contempt and uses coercion to achieve its end—all the while threatening to invade Taiwan—and the Philippines can and must field forces that can defend its sovereignty. The United States has every reason to support this endeavor.
Wilson Beaver is Senior Policy Advisor for Defense Budgeting and NATO Policy in the Douglas and Sarah Allison Center for National Security at The Heritage Foundation. Robert Peters is Senior Research Fellow for Strategic Deterrence in the Allison Center.
