Escalating tensions between China and Taiwan have forced the Philippines—whose northernmost point is less than 100 miles from Taiwan—to intensify its focus on a potential cross-strait conflict. Until now, Manila has prioritized internal security, particularly with regard to Islamist insurgents on the southern island of Mindanao, as well as Beijing’s growing encroachment into the Philippines’ exclusive economic zone (EEZ) in the South China Sea. But a future Taiwan scenario—how the Philippines might react and potentially support its security ally, the United States, if the latter were to intervene—is now beginning to take up more of Manila’s bandwidth.

Significantly, in a departure from past administrations, Philippine President Ferdinand Marcos Jr. has publicly discussed his growing concerns over Taiwan. Last summer, Marcos visited his northern army unit and remarked, “The external threat [from the Taiwan Strait] now has become more pronounced, has become more worrisome. And that is why we have to prepare.” In a February 2023 interview, Marcos said, “It’s very hard to imagine a scenario where the Philippines will not somehow get involved.”

Escalating tensions between China and Taiwan have forced the Philippines—whose northernmost point is less than 100 miles from Taiwan—to intensify its focus on a potential cross-strait conflict. Until now, Manila has prioritized internal security, particularly with regard to Islamist insurgents on the southern island of Mindanao, as well as Beijing’s growing encroachment into the Philippines’ exclusive economic zone (EEZ) in the South China Sea. But a future Taiwan scenario—how the Philippines might react and potentially support its security ally, the United States, if the latter were to intervene—is now beginning to take up more of Manila’s bandwidth.

Significantly, in a departure from past administrations, Philippine President Ferdinand Marcos Jr. has publicly discussed his growing concerns over Taiwan. Last summer, Marcos visited his northern army unit and remarked, “The external threat [from the Taiwan Strait] now has become more pronounced, has become more worrisome. And that is why we have to prepare.” In a February 2023 interview, Marcos said, “It’s very hard to imagine a scenario where the Philippines will not somehow get involved.”

Marcos has also presided over an expansion of the U.S.-Philippines Enhanced Defense Cooperation Agreement (EDCA), which authorizes the U.S. military to work alongside Philippine forces at nine designated bases for a range of potential future missions. Marcos insists that the new EDCA bases—three of which are on Luzon, the major Philippines island closest to Taiwan—will not be used for “offensive purposes,” but he has also noted that U.S. access to these sites will “prove to be useful for us should that terrible occurrence come about,” referring to a Chinese invasion of Taiwan.

Much of the operational and strategic planning revolves around Manila’s recently completed Comprehensive Archipelagic Defense Concept. This document has never been publicized, but Philippine experts have told me that it is an attempt to shift Manila’s mindset away from focusing on internal security threats in favor of external threats and ongoing intrusions, primarily by China against Philippine maritime borders.

U.S. and Philippine forces are contributing to the new defense strategy with an obvious focus on Taiwan. Within the last few months, the two countries have been constructing a joint facility on Itbayat in the Batanes province to counter China’s military presence in the area. It will reportedly house emergency equipment and provisions. The U.S. Army has referred to the facility as a “weatherproof warehouse for disasters” that may store equipment and supplies not only for natural disasters but war, as well. In May and June 2024, Washington and Manila held combat exercises on the islands in the Batanes, designed to defend them from attack. The fact that some of these exercises were integrated into the annual U.S.-Philippines Balikatan exercise is also significant because it demonstratively mainstreams the alliance’s attention on Taiwan-related threats.

And in response to then-Speaker of the House Nancy Pelosi visiting Taiwan in 2022 to meet with then-Taiwanese President Tsai Ing-wen, Manila later built a new Philippine Coast Guard station on Itbayat. In the words of Philippine National Security Advisor Eduardo Año, the new site was necessary because “China’s corresponding naval response was observed in the Luzon Strait” in the aftermath of Pelosi’s visit.

Manila’s newfound attention on Taiwan is likely to have several significant implications. For one, Washington and Manila will now have to collaboratively address another security threat beyond Beijing’s rising assertiveness within the Philippines’ EEZ in the South China Sea. Beyond their recent Taiwan-focused activities, this could mean that the U.S. military will seek additional force posture and presence options that leverage the Philippines’ unique geographic advantages. It could result, for example, in U.S. access to additional bases, particularly in the country’s north, and further alliance work on enhancing force interoperability through joint military drills and other activities.

For Manila, paying greater attention to threats in the north likely means broader and deeper collaboration with the U.S. military, which Philippine forces can benefit from. The challenge, however, is how to balance a greater focus on Taiwan with other security priorities. The Philippines would probably rather remain focused on Chinese encroachments into its EEZ; instead, the Taiwan Strait will distract Manila and force it to dedicate at least some resources to the area that otherwise could have been used in the South China Sea. The Philippine Coast Guard’s establishment of a station on Itbayat demonstrates how this is already happening.

China may benefit from the Philippines’ move to divide its forces, but this challenge can be mitigated if the U.S. military enhances its presence, as well. Manila’s recent decision to approve U.S. deployment of the mid-range Typhon missile system to its territory could reinforce deterrence. The missiles, which Philippine soldiers have already been trained to operate, cover not only much of the South China Sea but could also reach military bases on the Chinese coast.

Over the coming months and years, a number of factors could also disrupt Manila’s shift toward Taiwan. U.S. President Donald Trump, for example, may expect the Philippines to do more for its own defense rather than relying on U.S. security commitments. For example, when then-Philippine President Rodrigo Duterte attempted to cancel the U.S.-Philippines Visiting Forces Agreement, which is a key pact undergirding the two countries’ mutual defense treaty, during Trump’s first term, Trump replied, “I don’t really mind if they would like to do that. It will save a lot of money. My views are different than others.” However, recent Trump administration engagements with Philippine counterparts by U.S. Secretary of State Marco Rubio and National Security Adviser Mike Waltz have underscored that the alliance will remain “ironclad.”

Besides the uncertainty that Trump adds to the mix, new leadership in Manila could also seek to downgrade the U.S. military presence. Duterte’s daughter, Sara Duterte, currently serves as Marcos’s vice president and is quite popular. If she runs and wins the next presidential election in 2028, she could take her nation down the path laid out by her father of relying less on the United States in favor of closer ties with China.

Regardless of these and other uncertainties, China’s pressure campaign against Taiwan will not abate. This will keep the United States and Philippines increasingly engaged on cross-strait security with an eye toward limiting the impact a Taiwan conflict will almost certainly have on the Philippines.

Correction, Feb. 3, 2025: A previous version of this article mistitled former Taiwanese President Tsai Ing-wen. It has been fixed.