Imagine a place of stunning beauty — islands surrounded by bright turquoise waters, home to colorful coral reefs and peaceful beaches. Now picture that same place at the center of a dangerous global conflict. That’s what’s happening in the South China Sea, where geography meets geopolitics in a very tense way.
This sea is one of the world’s most important trade routes. Every year, trillions of dollars worth of goods pass through it. But today, it’s also a hotspot of tension — and the Philippines is right in the middle.
China has been making bold claims over large parts of the sea, backed up with actions that push boundaries — like using ships to block Filipino vessels, blasting them with water cannons, or getting into standoffs at sea. These aren’t full-on attacks, but they’re meant to send a message: back off.
For a long time, the Philippines didn’t fight back much. But now, things are changing. Under President Ferdinand Marcos Jr., the country is taking a stronger stance. It’s upgrading its military, working more closely with the U.S., and refusing to be pushed around.
Manila knows it can’t match Beijing’s power, but it’s not giving up either. It’s trying to protect its rights without sparking a war — a tough balancing act. With more joint military exercises and new defense deals, the Philippines is becoming a key player in the region’s future.
The world is watching as this small nation tries to hold its ground in a big-power game. And the outcome could shape the future of the entire Indo-Pacific.
Historical Context of U.S.-Philippine Ties
The friendship between the United States and the Philippines has been growing for more than 100 years. It started back in 1898, when the U.S. took control of the Philippines after Spain lost a war. The U.S. ruled the islands for almost 50 years, until the Philippines became independent in 1946, right after World War II.
In 1951, the two countries promised to protect each other with the Mutual Defense Treaty. That meant if one was attacked, the other would help. During the Cold War, the U.S. had big military bases in the Philippines, which were important for keeping an eye on what was happening across Asia.
But in 1992, those bases closed after the Philippine government decided not to renew the agreement. Still, the connection between the two countries stayed strong. In 1999, they signed a new deal called the Visiting Forces Agreement, which let U.S. troops come back — not to stay, but to train and work together with the Philippine military.
Now, with rising tensions in the region — especially with China — the U.S. and the Philippines are working even more closely than before. Their alliance is built on history, but it’s being shaped by today’s challenges.
The U.S. Military Deployment: Scope and Significance
The U.S. is significantly increasing its military presence in the Philippines, showing a stronger commitment to defending the region as tensions rise with China in the South China Sea. While some headlines may overstate the situation by saying things like “thousands of U.S. military vehicles are flooding the Philippines,” the real story is about a steady build-up of troops, advanced weapons, and closer cooperation between the two countries.
One major example of this partnership was Exercise Balikatan 2025 , held from April 21 to May 9. Now in its 40th year, this joint military drill involved more than 14,000 participants—9,000 from the U.S. and 5,000 from the Philippines—making it one of the largest exercises in recent years. Other countries like Australia, Japan, the UK, France, and several NATO members also sent observers or small teams, showing broad international support for the Philippines.
A big highlight of the exercise was the first-time deployment of the U.S. Navy-Marine Expeditionary Ship Interdiction System (NMESIS) to Batan Island, which sits in the Luzon Strait—a key location near Taiwan and the South China Sea. U.S. Marines from the 3rd Marine Littoral Regiment set up the missile system there. As Lt. Gen. Michael Cederholm explained, “Training here with our Philippine allies and using precision strike systems like NMESIS helps both countries better defend maritime areas that are spread out and remote.”
At the same time, HIMARS rocket launchers were used in live-fire drills on Palawan’s rugged western coast. These mobile artillery systems have been deployed in the Philippines since 2022, proving how quickly the U.S. can respond in faraway locations.
The U.S. is also helping upgrade military facilities in the Philippines. One important project is the construction of a boat repair and maintenance facility at Naval Detachment Oyster Bay in Palawan . This base supports patrols and supply missions to disputed areas like Second Thomas Shoal. The U.S. plans to invest $1 million to $5 million in this site by mid-2025.
All of these moves are made possible by the Enhanced Defense Cooperation Agreement (EDCA) , which gives the U.S. access to nine strategic bases in the Philippines for training, storage, and logistics. Both governments are now speeding up upgrades to these sites. In late 2024, Philippine Defense Secretary Gilberto Teodoro Jr. said making EDCA sites fully operational is now a top national security goal.
From a broader regional view, Col. Jason Armas, commander of the Marine Rotational Force-Darwin, said these efforts help strengthen the group’s ability to deal with challenges in the Indo-Pacific and promote peace in the region.
But it’s not just the U.S. doing the heavy lifting. The Philippines is also modernizing its own military—with strong support from the U.S. and others.
On May 20, 2025, the Philippine Navy commissioned its first guided-missile frigate , the BRP Miguel Malvar (FFG-06) . Built in South Korea, this ship can carry up to 16 VL-MICA missiles, giving the navy much more firepower. A second ship, the BRP Diego Silang (FFG-07) , is expected to join the fleet before the end of the year.
During its 127th anniversary celebration on May 22, the navy also showed off two new MANTAS T-12 unmanned surface vehicles (USVs) provided by the U.S. company MARTAC through the Foreign Military Sales program. These robotic boats will be used for surveillance, search and rescue, and even mine detection.
Looking forward, the Philippines has committed to a $35 billion, 10-year military modernization plan , shifting focus from fighting internal threats to building a stronger defense against outside enemies. This includes buying BrahMos anti-ship missiles from India and planning to acquire at least two submarines —a capability the country has never had before.
All of this shows a clear shift: the Philippines is no longer just a quiet ally. It’s becoming a stronger, more active partner in keeping the region safe—supported by a deepening alliance with the U.S. and a shared belief in international law and freedom of the seas.
China’s Reaction: “Furious” and “Alarmed”
China has reacted strongly to the growing U.S. military presence in the Philippines, calling it a dangerous move that threatens regional peace. Beijing sees the buildup as a direct challenge to its influence in the area and has been vocal in condemning what it calls American “bullying” and interference.
Tensions flared on May 22, 2025 , when a Chinese Coast Guard ship used water cannons against a Philippine vessel near Sandy Cay. The attack reportedly caused damage to the Filipino ship and injured some crew members. In response, China’s Foreign Ministry spokesperson Mao Ning defended the action, saying the coast guard “always follows laws and regulations” when carrying out its duties. But critics say this is just a cover for increasingly aggressive behavior by China in disputed waters.
A month earlier, during the Balikatan 2025 military exercises, the U.S. deployed advanced missile systems to the Philippines. Chinese Foreign Ministry spokesperson Guo Jiakun strongly criticized the move, accusing the U.S. of “bullying and hegemony.” He also gave a serious warning: “Those who play with fire will get burned.” That phrase is often used by Beijing when talking about issues like Taiwan or foreign military involvement in the region.
Chinese military analyst Zhang Junshe added that the U.S. was setting up a network of missile bases across the Philippines—ranging from long-range to short-range weapons—that could target China’s southeastern coast. He warned that if conflict ever broke out, those bases would become prime targets for China. He also said the Philippines’ decision to host U.S. forces was like “inviting a wolf into your house,” suggesting that Manila could end up paying a heavy price for its alliance with Washington.
Diplomatic Protests and Political Pressure
China has not limited its objections to rhetoric; it has launched formal diplomatic protests against the Philippines and the United States. On November 8, 2024, following the Philippine government’s passage of the Maritime Zones Act and Archipelagic Sea Lanes Act, Beijing issued a scathing response. Spokesperson Mao Ning claimed that the legislation “illegally included” Panatag Shoal (Scarborough Shoal) within Philippine waters and accused Manila of using domestic law to solidify the 2016 arbitral ruling—an award China refuses to recognize. “This move severely violates China’s territorial sovereignty,” she declared, reiterating Beijing’s long-standing stance that the South China Sea disputes fall outside the bounds of international arbitration.
The following day, China summoned the Philippine ambassador for an urgent protest, signaling the seriousness with which it views even legal maneuvers that challenge its maritime claims. More recently, on February 25, 2025, the Chinese Foreign Ministry issued another stern warning in response to the U.S. deployment of the Typhon missile system in the Philippines. Spokesperson Guo Jiakun emphasized that China “will not stand idly by when its interests are threatened,” reinforcing Beijing’s readiness to retaliate against perceived strategic encirclement.
China Raises Flag on Disputed South China Sea Island — Philippines Responds with Bold Move
Escalation Through “Gray Zone” Tactics
Despite the visible presence of U.S. forces and growing defense cooperation between Manila and Washington, China has not relented in its use of aggressive “gray zone” tactics—actions below the threshold of conventional warfare but aimed at intimidation and coercion. These tactics have grown increasingly violent and direct. One of the most alarming incidents occurred on June 17, 2024, when Chinese coast guard personnel allegedly boarded a Philippine Navy inflatable boat during a resupply mission to Second Thomas Shoal. Armed with knives and axes, they reportedly damaged the vessel, destroyed sensitive equipment, and seized firearms. One Filipino sailor lost a finger, and others were injured—marking a serious escalation from previous confrontations involving only water cannons.
Such behavior has continued unabated. On May 22, 2025, the Philippine Bureau of Fisheries and Aquatic Resources (BFAR) reported that Chinese vessels once again used water cannons and even sideswiped the BRP Datu Sanday during a marine research mission near Sandy Cay. The attack resulted in damage to the ship’s port bow and smokestack. BFAR condemned these “aggressive and illegal acts,” calling attention to China’s increasing willingness to obstruct even scientific missions.
China has also expanded its legal framework to support such maritime aggression. On June 15, 2024, the China Coast Guard issued new guidelines allowing its officers to use lethal force against foreign vessels in disputed waters. The rules also permit detention of “trespassers” for up to 60 days without trial. While cloaked in legal language, these measures effectively authorize further gray zone escalation and lend legitimacy—at least domestically—to China’s hostile actions in contested maritime zones.
Implications and Outlook
The growing military cooperation between the United States and the Philippines is fundamentally designed to strengthen their combined deterrence against aggression in the South China Sea. This approach rests on the belief that maintaining a visible and credible defense posture is key to discouraging potential adversaries. Philippine Brigadier General Michael Logico captures this perfectly when he says, “A peaceful region can only be maintained through a proper balance of strength between opposing forces.” This principle has moved from theory into action through increasingly frequent and complex joint exercises. For example, the 40th iteration of Exercise Balikatan, held from April 21 to May 9, 2025, involved over 14,000 U.S. and Filipino participants—significantly larger than previous years. It also marked the first deployment of the Navy-Marine Expeditionary Ship Interdiction System (NMESIS) to Batan Island, a strategic site near Taiwan. U.S. Marine Corps Lieutenant General James Glynn emphasized the resolve behind these efforts during the opening of Balikatan, stating, “We will demonstrate not just our will to uphold our mutual defense treaty in existence since 1951 but our matchless capability to do so.” The increasing scale and sophistication of these joint drills, paired with upgrades like the new boat repair facility at Naval Detachment Oyster Bay (expected to be operational by mid-2025), sends a clear message: both nations are firmly committed to collective defense and upholding a rules-based regional order.
Despite the clear aim of deterrence, the rising military activity in the South China Sea inevitably stirs concerns about the risk of miscalculations or unintended escalation. The region remains a precarious flashpoint where the close proximity of military forces from multiple nations raises the chances of accidental clashes that could spiral out of control. While China’s provocations undeniably heighten tensions, some analysts caution that Washington’s increasingly assertive responses could also contribute to a more volatile environment. The deployment of advanced missile systems like NMESIS, which Beijing perceives as a direct threat to its mainland, adds fuel to the strategic competition. As one expert noted, “Although none of the parties appear to seek open conflict, increasing militarization and patrols have raised the risk of incidents that could escalate tensions.” The incident on June 17, 2024, when Chinese Coast Guard personnel reportedly used knives and axes against Philippine sailors near Second Thomas Shoal, vividly illustrates the delicate and dangerous nature of these encounters, where escalation can happen even without any deliberate intent for full-scale conflict.
Central to the Philippines’ approach—and its deepening alliance with the United States—is a steadfast assertion of its sovereign rights, firmly grounded in international law. Manila consistently points to the 2016 ruling by the international arbitral tribunal, which decisively rejected China’s expansive claims based on the “nine-dash line” as having no legal foundation under the United Nations Convention on the Law of the Sea (UNCLOS). Despite China’s outright rejection of the ruling, it remains a cornerstone of the Philippines’ legal and diplomatic stance. Philippine officials have repeatedly stressed their commitment to upholding their “sovereignty, sovereign rights and jurisdiction in accordance with international law, including the 1982 UNCLOS and the 2016 arbitral award.” This commitment is reinforced by recent domestic legislation such as the Philippine Archipelagic Sea Lanes Act and the Philippine Maritime Zones Act, both signed in November 2024 to align national laws with international maritime norms. Manila’s ongoing exposure of China’s “gray zone” tactics—highlighted by detailed reporting and photographic evidence of aggressive incidents like the May 22, 2025 water cannon attack near Sandy Cay—serves as a deliberate effort to rally international support and underscore Beijing’s disregard for legal norms.
At the foundation of this evolving security architecture is the enduring U.S.-Philippines Mutual Defense Treaty, signed in 1951, which continues to anchor their security partnership. Philippine Ambassador to Washington, Jose Manuel Romualdez, often highlights the “ironclad commitment” of this treaty, reinforcing its lasting significance amid shifting regional threats. This strong alliance was reaffirmed during U.S. Defense Secretary Pete Hegseth’s visit to Manila in March 2025. Addressing Philippine President Ferdinand Marcos Jr., Hegseth remarked, “There is a very real reason why our first trip and our first visit, is here to your great country.” He further declared, “Our partnership not only continues today, but we are doubling down on that partnership, and our ironclad alliance has never been stronger.” This sustained high-level engagement goes beyond exercises and diplomacy, extending to substantial military financing—such as the reported $500 million pledge in mid-2024 for Philippine military modernization—and cooperation in intelligence sharing, cybersecurity, and the transfer of advanced defense technology. These efforts include American-provided unmanned surface vessels and prospective acquisitions like the Typhon missile launchers, all aimed at enhancing the Philippines’ indigenous defense capabilities and reinforcing the collective security framework in the Indo-Pacific region.
Conclusion: A New Dynamic in the Indo-Pacific
The U.S. military buildup in the Philippines, driven by China’s increasingly assertive actions, marks a major shift in the Indo-Pacific geopolitical landscape. While this enhanced presence aims to strengthen deterrence and support Philippine sovereignty, it simultaneously heightens strategic competition in the South China Sea, making careful diplomacy and clear communication essential to avoid dangerous escalation. Tensions have already surged significantly, underscored by recent incidents such as the Chinese Coast Guard’s seizure of a disputed reef alarmingly close to a vital Philippine military outpost, illustrating just how volatile the situation has become.
Second Thomas Shoal Resupply Mission: Did Manila Ask Beijing?
