The Russian invasion of Ukraine on February 24, 2022, which is now entering eight months, caught the member states of the Association of Southeast Asian Nations (ASEAN) by surprise. Among these, the Philippines stands out as particularly dazed and bewildered by the invasion. At the onset of the war, the Duterte Administration announced that it would be adopting a policy of neutrality. Eventually, however, the administration condemned the invasion and warned that if the conflict were to spill over to Asia, the president would be offering access to Armed Forces of the Philippines’ (AFP) military facilities to the country’s only formal treaty ally, the United States. The shift in Manila’s position underscores the uncertainty and concerns of many Asian countries for the ongoing military conflict in Eastern Europe, as well as with rising tensions in the Taiwan Strait.
On March 10, the Philippine Ambassador to Washington, Jose Manuel Romualdez, announced that then-President Duterte was ready to open the country’s military facilities to American forces if Russia’s invasion of Ukraine were to turn for the worse and embroil the United States in the war. He also revealed that the “President stated that if they [the United States] [were to ask] for the support of the Philippines, it’s obvious that, of course, if push comes to shove, the Philippines will be ready to be part of the effort, especially if this Ukrainian crisis spills over into the Asian region.” He added that the president instructed him to give assurances to the United States “that if ever needed, the Philippines is ready to offer whatever facilities or whatever things that the United States will need being a major—our number one ally.” Ambassador Romualdez specifically stated that the president indicated that in the event of an emergency, “the Philippines would allow US forces to return to the former naval station at Subic Bay and the nearby Clark Air Base.”
Through the Prism of the Ukraine-Russia War
The Duterte Administration’s unexpected gesture of offering the former US military facilities to Washington was widely seen as a surprise. This was because his administration had previously been ambivalent—if not openly dismissive—about the Philippines’ alliance with the United States. In 2016, for instance, Duterte had criticized the United States for voicing its concerns over the Philippine government’s bloody war on drugs, and announced his intention to wean the Philippines away from the alliance and to pivot to China. Indeed, his announcement of opening Philippine military facilities to US forces marked a notable departure from his usual anti-American tirades. However, this raised the question of whether or not there was any actual possibility that the Ukraine-Russia War would spread from Eastern Europe to East Asia. Exactly how such an event could occur is unclear. What was revealing, however, was that the Duterte Administration’s pledge of support to the United States in any conflict in Asia appeared to extend beyond the text of the 1951 Mutual Defense Treaty (MDT). 
The offer was seen as an attempt to recalibrate the alliance as the Duterte Administration’s term was about to end in June 2022. More significantly, it also revealed an underlying fear among many Southeast Asian states that Russia’s invasion of Ukraine would encourage China to follow suit in the Taiwan Strait—and potentially in the South and East China Seas—thereby causing collateral instability throughout the region. For states across the region, including the Philippines, the invasion set a worrying precedent, especially given converging Sino-Russian goals of challenging the US-led rules-based international order. It also raised the specter of Beijing taking a page out of Russia’s playbook by applying gray zone operations, conducting hybrid warfare, and using force to acquire and eventually annex disputed territories.
Across the Taiwan Strait, China could pursue an intensified campaign of coercion, threats, and pressure, much like President Putin did before the actual invasion of Ukraine. This could cause the United States to be caught unprepared and force Taiwan to make extended diplomatic and military concessions to China to avoid the risk of full-scale armed conflict. China could also mount an armed invasion of the island democracy to retake what it deems as a renegade province. In the South China Sea, again borrowing from Russia’s playbook, China could potentially accuse the United States of naval aggression or excessive intervention in maritime disputes, providing a pretext for “defensive” operations to seize the Spratly Islands and the rest of the South China Sea from other claimant states.
Defense planners in Manila are also aware that China’s invasion and occupation of Taiwan would substantially boost Beijing’s strategic position, as it would enable the People’s Liberation Army Navy (PLAN) to impede the US 7th Fleet’s ability to conduct naval and air operations in the Philippine Sea. In turn, this could prevent the United States from honoring its treaty obligations to Asian allies like the Philippines. Filipino defense planners are also cognizant that China’s control of Taiwan will enable it to base its growing fleet of attack and ballistic missile submarines in the island’s ports—allowing it to threaten Northeast and Southeast Asian shipping lanes—while also strengthening its naval presence in the “First Island Chain” with sea-based nuclear forces.
Furthermore, the Philippines and other Southeast Asian countries like Vietnam, Malaysia, and Brunei all have lingering unresolved territorial and maritime disputes with China in the South China Sea. This makes Manila wary that China might emulate Russia’s approach to Ukraine: escalating grey zone/hybrid operations into full-scale armed warfare. This could involve the PLAN relying on civilian maritime agencies, such as the Chinese Coast Guard (CCG) and the Chinese Maritime Militia (CMM, 中國海上民兵), to take a leading role in handling these disputes. 
This underlying fear of China emulating Russian tactics in Ukraine, and using force to change the status quo in the Taiwan Strait and the South China Sea, likely played a major role in driving the Duterte Administration to strengthen its security ties with the United States. A conflict between the United States and China over Taiwan would almost inevitably drag in the Philippines due to the nation’s geographical proximity to Taiwan. Furthermore, because of the MDT, Manila is bound to extend assistance to the United States in case of a conflict with China.
Will the Marcos Administration Follow Suit?
The Ukraine-Russia War has made the Philippines aware of the possibility that China could mount a similar approach to retake Taiwan. It became apparent to the Duterte Administration that, given the Philippines’ proximity to Taiwan, the United States would likely look at its treaty ally for access were it to mount a major military response to a Chinese attack on the self-governing island. Earlier, during bilateral consultations in November 2021, the two countries agreed to resume the construction of US facilities inside five Philippine Air Force (PAF) airbases that were chosen by the previous Aquino Administration in 2016, based on the 2014 Philippine-U.S. Enhanced Defense Cooperation Agreement (EDCA).
On March 31, 2022, the Philippines and the United States held an unusually large joint military exercise in response to the perceived growing threat from China, as well as both countries’ wariness of the expanding Sino-Russian security partnership. The military exercise included conventional warfighting scenarios such as amphibious landings, airstrikes, and ship movements aimed at enhancing the two allies’ crisis planning and response capabilities. These operations, the 37th iteration of the so-called Balikatan Exercise, also involved several smaller bilateral and trilateral military exercises all over the Philippines. More significantly, they showed the Biden Administration’s efforts to reinforce its relations with its formal treaty allies in Southeast Asia—and to address the regional perceptions that Washington is paying more attention to its new security partners, such as Singapore and Vietnam, at the expense of longtime allies like Thailand and the Philippines.
It is still a matter of speculation as to whether or not the administration of Ferdinand Marcos Jr. will subscribe to this policy of offering the United States logistical support in the event of a possible US-China confrontation over Taiwan. However, what people are now describing as the Fourth Taiwan Strait Crisis—ostensibly triggered by Speaker Nancy Pelosi’s visit to Taiwan— has created the opportunity for newly elected President Marcos to express his plan to pursue close economic relations with China, while also balancing the Philippines’ deep security ties with the United States. Responding to US Secretary of State Antony Blinken’s reaffirmation of the 1951 MDT, Marcos replied: “We cannot, we can no longer isolate one part of our relationship from the other. We are too closely tied because of the special relationship between the United States and the Philippines and the history we share.” In his subtle way, Marcos assured Secretary Blinken that the US-Philippine alliance is rock solid, even in the face of the 21st-century Taiwan Strait Crisis.
On the sidelines of the 77th session of the United Nations General Assembly in September, President Marcos and President Joe Biden reaffirmed the two allies’ “ironclad commitment” to the 1951 Mutual Defense Treaty, with President Biden emphasizing that the U.S. would defend the Philippines if attacked by a foreign aggressor. A few weeks later, the two countries’ defense secretaries met at the U.S Indo-Command, where they reiterated their countries’ commitment to the MDT by enhancing maritime cooperation and improving their respective armed forces’ interoperability and information sharing. Both defense secretaries saw the necessity of improving and modernizing their alliances. This will require the two allies to accelerate the implementation of the 2014 Enhanced Defense Cooperation Agreement (EDCA) by concluding infrastructure enhancements and repair projects at existing EDCA-agreed locations inside five Philippine Air Force (PAF) bases all over the country. This will also entail the two allies exploring new locations that will be built to create their credible mutual defense posture. Finally, the two defense secretaries revealed the signing of the U.S-Philippine Maritime Framework intended to jump-start the two countries’ maritime cooperative activities in the South China Sea, which might include the resumption of joint naval patrols by the U.S. and Philippine navies. These are clear indications that President Marcos Jr. is following former President Duterte’s efforts to modernize the alliance to help secure the Philippines, address regional security challenges, and promote peace and security in the Indo-Pacific.
The main point: The Russian invasion of Ukraine and rising tensions over Taiwan have led the Philippines to revive and strengthen its longstanding security ties with the United States, to include renewed prospects for US forces to use facilities in the Philippines in the event of a potential conflict over Taiwan.
 Per the 1951 Philippine-U.S. Mutual Defense Treaty, the two allies will consult each other in the event of an armed attack. President Duterte committed to providing U.S. access to five Philippine Air Force (PAF) bases in case of an armed attack against US forces in the region by Russia or China.
 Alexander Chieh-cheng Huang, “The PLA and Near Seas Maritime Sovereignty Disputes,” The People’s Liberation Army and Contingency Planning in China (eds) Andrew Scobell, Arthur S. Ding, Phillip C. Saunders, and Scott W. Harold (Washington DC: National Defense University, 2015). 279-299.