Features | Security | Southeast Asia

The Next Challenge Facing the US-Philippine Alliance, and How They Plan to Overcome It

This year’s Balikatan exercise oriented itself more closely than ever to the Taiwan Strait — and the possibility of a future conflict over the island.

Philippine Defense Secretary Gilberto Teodoro and Japanese Defense Minister Koizumi Shinjiro pose for a group photo with military personnel from the Philippines, the United States, Australia, and Japan, and other civilian attendees following a joint task force maritime strike event during Exercise Balikatan 2026 at Paoay Sand Dunes, Philippines, May 6, 2026.

For 18 days in late April and early May, a force of 17,000 personnel, primarily from the Philippines, Japan, and the United States, gathered across an increasingly strategically relevant Southeast Asian archipelago for Balikatan 2026. Despite the insistence of exercise public affairs officers, there was only one adversary that these drills could be preparing to confront.

U.S. Indo-Pacific Command (INDOPACOM) chief Adm. Samuel Paparo proclaimed this Balikatan as a “rehearsal” for the defense of the Philippines. This was a significant step-up from past iterations, which focused on generic internal security issues and humanitarian operations.

The shift began in earnest in Balikatan 2022, a year in which Washington and Manila started to revitalize a relationship that had become strained under President Rodrigo Duterte. Their focus was to put up a signal to deter escalatory actions from Beijing’s maritime forces in the South China Sea. Balikatan’s gaze shifted west, with a milestone ship-sinking demonstration within 250 kilometers of Scarborough Shoal that was attended by Philippine President Ferdinand Marcos Jr. in 2023.

In 2024 and 2025, the focus of the drills slowly but surely oriented toward the northern edges of Luzon, in close proximity to Taiwan. The Batanes Island Group, Ilocos Norte, and Cagayan received an influx of Philippine and American troops. They were then reinforced by new basing agreements, missile deployments, and military construction projects in key areas.

2026 not only continued this pattern, but significantly expanded the drills’ intensity, focus, and complexity across multiple realms crucial in a potential contingency involving Manila, Washington and Beijing – whether one in the South China Sea or the Luzon Strait.

Balikatan’s evolution has always reflected the deepest concerns and priorities of the U.S.-Philippine alliance. In 2026, the exercise now reflects the focal point of Indo-Pacific priorities from the U.S. and its allies in the northern reaches of the Philippines.

Balikatan 2026’s Circumstances and Challenges 

Historically, those who are on the defensive in the Philippine archipelago have a poor track record of success. Between 1898 and 1944, all invasions of the Philippines succeeded despite the best efforts of the defender.

Today’s circumstances are perhaps some of the most challenging for the defender since the Japanese and American invasions during the Pacific War.

Aside from solidifying Beijing’s territorial claims, the People’s Liberation Army Southern Theater Command has a plethora of warships, fighters, bombers, reconnaissance assets, and amphibious-capable contingents that can be rapidly mobilized against the Philippines. These advanced and multi-mission assets could be staged and sustained up to 230 kilometers from Philippine shores at a collection of artificial island military bases in the Spratly Islands. Chinese forces can also call upon a vast arsenal of cruise, ballistic, and hypersonic missiles.

They are further supported by hundreds of paramilitary vessels from the Chinese Maritime Militia and China Coast Guard, which expand maritime domain awareness and sensor coverage for Chinese commanders. This force has demonstrated its flexibility against the Philippines over the last decade through China’s hybrid approach toward asserting its territorial claims in the South China Sea. With an overmatch this severe in peacetime, it is hard to emphasize how drastic the situation could be in wartime.

Philippine Marines with the 68th Marine Company, Force Reconnaissance Group, prepare to insert into the Batanes island chain for maritime key terrain security operations during Exercise Balikatan 2026 at Cagayan North International Airport, Lal-lo, Philippines, Apr. 26, 2026. (U.S. Marine Corps photo by Sgt. Iyer Ramakrishna)

To further complicate matters, the infiltration of Philippine society by what the Armed Forces of the Philippines (AFP) calls “United Front Works” (UFW) has the potential to inflict serious damage on the country’s infrastructure and response capabilities in the event of a conflict. In recent years, suspected Chinese spies have been detained collecting sensitive information near government and military facilities in Manila, Subic Bay, and Palawan. A mayor of a town in Luzon was also revealed to be a Chinese national in 2024. Meanwhile, nearly half of the Philippine national power grid is controlled by China.

It is not difficult to see how an adversary like China might exploit these gaps in the event of a conflict.

It is these challenges that U.S. and Philippine planners must contend with, and are attempting to counter through the recent Balikatan drills. They face an enormous challenge from an adversary with numerous capabilities that can be quickly mobilized within the region and potential avenues for disruption from within the Philippines itself. 2026’s iteration of the exercises showcased some of the most intensive efforts to defend against these threats.

Luzon’s Importance in a Taiwan Contingency 

For many, Philippine national security begins and ends with the South China Sea – or at least that might have been the case in the 2010s. A new focus for Manila is on the country’s northern territories and how a Chinese invasion of Taiwan might impact them.

Within the last two years, the Philippine political and military leadership, from AFP Chief of Staff Gen. Romeo Brawner to President Marcos, have repeatedly stated that whatever happens in Taiwan will also affect the Philippines. Alongside the large number of Overseas Filipino Workers residing in Taiwan, Luzon’s geographical proximity has been frequently cited. Located only 320 kilometers away from Taiwan, Luzon is the closest landmass to Taiwan aside from mainland China.

From the deployment of mobile missile launchers and dispersed combat aircraft, the devastating potential of U.S. forces from Luzon to take part in offensive operations against China or defensive operations in support of Taiwan cannot be understated. Strikes from Luzon can easily reach the waters around Kaohsiung, Taipei’s largest port and likely site of a Chinese landing in the event of an invasion.

A string of Philippine islands dot the strait between Luzon and Taiwan. If missiles and sensors were stationed on these islands, they could play an important role in the event of an attack or defense of Taiwan. From the Batanes and Babuyan Islands, a country could potentially control, or at least hinder, another’s ability to transit the first island chain.

These geographical realities have resulted in a security dilemma for all parties involved. The Philippines wants to deter China from eyeing the islands for its own military use. While supporting these efforts, the U.S. wants to deter China but may also view the strategic northern areas as a support base for Taiwan contingency operations. Beijing’s options during an invasion of Taiwan would be constrained if these strategic areas are not dealt with in a manner that keeps interventionist forces out.

Influencing all of these perspectives are recent territorial tensions,........

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