US and Japan back Philippine maritime drills amid China Coast Guard confrontations

The Philippines, the United States and Japan completed five days of maritime exercises in the South China Sea on July 25, 2026, as confrontations between Philippine and Chinese vessels intensified around Second Thomas Shoal and Scarborough Shoal.

The Multilateral Maritime Cooperative Activity was conducted from July 21 to July 25 within the Philippine exclusive economic zone. The exercise brought together warships, coast guard vessels, fighter aircraft, surveillance platforms and military helicopters from the three countries.

The drills included anti-submarine warfare training, replenishment operations, maritime domain awareness missions and coordinated ship movements. The three participating countries presented the exercise as an effort to strengthen tactical interoperability, regional cooperation and navigation under international law.

The timing gave the exercise greater strategic importance. The drills began one day after a confrontation at Second Thomas Shoal in which Philippine personnel said Chinese Coast Guard officers struck Filipino sailors with wooden poles, injuring two people.

Further confrontations occurred near Scarborough Shoal while the exercise was underway. Philippine authorities accused Chinese Coast Guard vessels of firing water cannons at government fisheries ships and conducting manoeuvres that created a serious collision risk.

China rejected the Philippine version of events and accused Philippine vessels of entering contested waters despite warnings. The China Coast Guard said its tracking, interception and water-cannon actions were lawful measures used to remove vessels it described as intruders.

The military exercise did not directly intervene in those confrontations. However, the presence of United States and Japanese forces demonstrated that repeated maritime incidents are increasingly linked to wider alliance planning across the Indo-Pacific region.

Why did the United States and Japan join five days of Philippine South China Sea drills?

The exercise was designed to improve the ability of Philippine, United States and Japanese forces to operate together during maritime security missions. Interoperability covers communications, navigation, surveillance, aircraft coordination, logistics and the procedures used when several militaries operate within the same area.

The participating forces conducted anti-submarine warfare training, which is among the most technically demanding forms of naval cooperation. Detecting and tracking submarines requires ships, aircraft, sensors and command centres to share information rapidly while distinguishing military activity from normal maritime traffic.

The exercise also included replenishment at sea and vertical replenishment. These operations allow vessels to receive fuel, supplies and equipment without returning to port, increasing the duration and geographic reach of maritime deployments.

Maritime domain awareness was another central component. The term covers the collection and analysis of information involving vessels, aircraft, weather conditions and activities that may affect national security, navigation or commercial operations.

For the Philippines, stronger surveillance is important because the country must monitor a large maritime area containing disputed shoals, fishing grounds and military outposts. The Philippines has repeatedly argued that limited ships and aircraft make it difficult to maintain a continuous presence throughout its exclusive economic zone.

The United States and Japan have expanded maritime cooperation with the Philippines as tensions with China have increased. The drills allow the three countries to practise operational procedures before a crisis, rather than attempting to establish coordination after an emergency has already begun.

The exercise also reinforced the political message that the United States and Japan support Philippine access to waters claimed by Manila under the United Nations Convention on the Law of the Sea. China views this cooperation as external interference in disputes that Beijing says should be managed directly by regional claimants.

Which warships and aircraft participated in the July 21 to July 25 maritime exercise?

The United States Navy deployed USS Santa Barbara, an Independence-class littoral combat ship, and a P-8A Poseidon maritime patrol and reconnaissance aircraft. The P-8A Poseidon can support surveillance, anti-submarine warfare and the monitoring of maritime activity across large distances.

The Japan Maritime Self-Defense Force participated with JS Yudachi, a Murasame-class destroyer. The presence of a Japanese destroyer reflected Japan’s expanding security cooperation with Southeast Asian countries and Tokyo’s growing concern about maritime pressure across the East China Sea, South China Sea and western Pacific.

The Philippine Navy deployed BRP Antonio Luna, a Jose Rizal-class guided-missile frigate, along with an AW109 helicopter. BRP Antonio Luna is one of the Philippine Navy’s principal surface combatants and provides capabilities involving surveillance, anti-submarine operations and maritime defence.

The Philippine Coast Guard contributed BRP Malabrigo, a Parola-class patrol vessel. Including the Philippine Coast Guard was significant because many confrontations with China involve coast guard and civilian government vessels rather than conventional naval forces.

The Philippine Air Force deployed two FA-50 fighter aircraft, two A-29B Super Tucano light attack aircraft, one C-208B intelligence, surveillance and reconnaissance aircraft and one Sokol search-and-rescue helicopter.

The mixture of military and coast guard assets allowed the exercise to cover several operational scenarios. The forces practised communication between ships and aircraft, coordinated maritime surveillance and developed procedures for transferring supplies while underway.

The participating platforms also demonstrated the different roles each country could provide during a future maritime emergency. The Philippines contributes local access and geographic knowledge, while the United States and Japan offer advanced surveillance, logistics and naval capabilities.

The exercise remained a training activity rather than an armed operation directed against a named country. Its scope nevertheless showed that trilateral cooperation has moved beyond symbolic port visits towards complex operational integration.

How did the drills overlap with confrontations at Second Thomas Shoal and Scarborough Shoal?

The exercise began shortly after a confrontation at Second Thomas Shoal, where the Philippines maintains a military outpost aboard BRP Sierra Madre. The ageing Second World War-era vessel was deliberately grounded at the shoal in 1999 to support Manila’s territorial position.

The Philippines regularly delivers food, fuel and other supplies to personnel stationed aboard BRP Sierra Madre. China attempts to monitor and restrict those missions because Beijing claims sovereignty over the shoal and surrounding waters.

Philippine authorities said Chinese Coast Guard personnel struck Filipino sailors with wooden poles during the July confrontation, injuring two people. China said the Philippine personnel had attacked Chinese officers first with oars and long sticks and accused Philippine vessels of ramming Chinese boats.

The competing accounts illustrate the central difficulty surrounding South China Sea incidents. Both governments publish footage, statements and maps intended to establish that the other side initiated the confrontation.

Scarborough Shoal became another flashpoint during the trilateral drills. Philippine government fisheries vessels attempted to operate near the shoal, while China Coast Guard ships used water cannons and interception manoeuvres to drive them away.

One Chinese vessel reportedly approached a Philippine ship at a distance of approximately seven metres, creating fears of a collision. Philippine authorities described the action as dangerous and unprofessional, while China maintained that Philippine ships had ignored warnings.

The confrontations occurred during a week of regional diplomatic meetings in Manila. Association of Southeast Asian Nations foreign ministers discussed South China Sea incidents and reiterated concern over actions that endanger personnel or damage the marine environment.

The combination of diplomacy, military exercises and physical confrontations demonstrates how difficult it has become to separate crisis management from alliance signalling. Negotiations continue, but coast guard and military forces are simultaneously preparing for further incidents.

What does the 2016 arbitral ruling mean for the Philippines-China maritime dispute?

The Philippines initiated international arbitration against China under the United Nations Convention on the Law of the Sea. The arbitral tribunal issued its decision in July 2016.

The tribunal concluded that China’s claim to historic rights across much of the South China Sea had no legal basis where it exceeded the maritime entitlements permitted under the convention. The ruling also examined the legal status of several disputed maritime features.

China rejected the proceedings and has refused to recognise the ruling. Beijing maintains that it possesses sovereignty and historic rights in the South China Sea and argues that territorial disagreements should be settled through negotiation.

The Philippines treats the ruling as a central legal foundation for its maritime claims. Manila argues that areas including the waters around Scarborough Shoal and Second Thomas Shoal fall within Philippine maritime entitlements.

The tribunal did not resolve every sovereignty dispute concerning islands and rocks. Maritime entitlement and ownership of territory are separate legal questions, allowing China and the Philippines to continue presenting competing claims.

The ruling also lacks an automatic enforcement mechanism. International courts and tribunals depend on governments to comply, while the United Nations Convention on the Law of the Sea does not provide a naval force capable of implementing decisions.

The Philippines has therefore combined legal arguments with coast guard deployments, military modernisation and security partnerships. China has relied on its much larger coast guard, navy and maritime militia presence to maintain physical control around contested features.

The result is a continuing gap between legal entitlement and operational access. A country may possess a strong legal argument but still struggle to reach waters where another state maintains a larger permanent presence.

Why is the United States-Philippines defence treaty central to every new maritime clash?

The United States and the Philippines are bound by the 1951 Mutual Defense Treaty. The agreement requires both countries to respond to armed attacks affecting their forces, public vessels or aircraft in the Pacific region.

Washington has repeatedly stated that the treaty applies to Philippine armed forces, government vessels and aircraft operating in the South China Sea. That clarification is intended to deter an attack that could cause deaths or destroy a Philippine government asset.

The treaty does not mean that every water-cannon incident or collision automatically results in military action. Governments would need to assess the scale, intention and consequences of an incident before determining the appropriate response.

The danger lies in gradual escalation. Water cannons, ramming, boarding attempts and the use of poles or handheld weapons may be intended to remain below the threshold of conventional armed conflict.

However, even a limited confrontation could become more serious if a vessel capsizes, personnel are killed or military aircraft become involved. The narrow distance between coast guard vessels also increases the possibility of an accidental collision.

The presence of Japanese forces adds another strategic layer. Japan does not have a mutual defence treaty with the Philippines equivalent to the United States agreement, but Tokyo has expanded security assistance, equipment transfers and joint exercises with Manila.

Japan’s involvement demonstrates that South China Sea security is no longer treated only as a dispute between the Philippines and China. Tokyo views the rules governing maritime access as connected to its own concerns involving the East China Sea and regional shipping.

The trilateral format creates stronger deterrence but also raises the stakes. China may perceive the exercises as evidence that the Philippines is internationalising the dispute and helping the United States and Japan contain Chinese influence.

Could the expanded trilateral exercises prevent conflict or increase the risk of escalation?

Supporters of the exercises argue that prepared and interoperable forces are less likely to make dangerous mistakes during a crisis. Common procedures can improve communication, navigation and the ability to rescue personnel following an accident.

The exercises may also discourage more aggressive conduct by demonstrating that the Philippines does not operate alone. A potential opponent must consider the possibility of diplomatic, logistical or military support from Manila’s partners.

The same activity can also be interpreted differently by China. Beijing may respond to stronger Philippine partnerships by increasing patrols, conducting counter-exercises or deploying larger vessels near disputed areas.

An expanding cycle of drills and counter-deployments can reduce the physical space available for manoeuvring. More ships and aircraft create more opportunities for close encounters, radar tracking and disputed warnings.

The most immediate requirement is therefore reliable communication between Chinese and Philippine authorities. Crisis hotlines and agreed operational procedures could help prevent a collision or injury from producing a broader confrontation.

The Association of Southeast Asian Nations and China have spent years negotiating a South China Sea code of conduct. Regional ministers reported progress in July 2026 and maintained an objective of concluding negotiations during the year.

A code of conduct could establish expectations involving vessel behaviour, emergency communication and the treatment of personnel. Its value would depend on whether the language is binding, enforceable and accepted during real confrontations.

The July exercise demonstrates that deterrence and diplomacy are developing in parallel. The Philippines is strengthening military partnerships while continuing to support negotiations intended to prevent an armed conflict.

Why does the South China Sea dispute matter for regional trade and global supply chains?

The South China Sea is one of the world’s most heavily used maritime trade routes. Energy products, manufactured goods, raw materials and consumer products move through the region between East Asia, Southeast Asia, the Middle East and Europe.

A serious confrontation could disrupt shipping schedules and increase insurance costs even without closing the entire waterway. Commercial operators respond quickly when military or coast guard activity creates uncertainty near established routes.

The area also contains important fishing grounds that support coastal communities throughout Southeast Asia. Access disputes affect livelihoods, food security and relations between fishing communities and enforcement agencies.

The seabed may contain oil and natural gas resources, although commercial development is complicated by overlapping territorial claims. Energy exploration projects can become politically sensitive when China and Southeast Asian states disagree over licensing rights.

The Philippines has an economic interest in maintaining access to resources within its exclusive economic zone. China seeks to protect its broader strategic and territorial position while resisting activities that Beijing believes undermine Chinese sovereignty.

The United States and Japan have an interest in preserving open shipping and preventing one country from establishing exclusive control over the waterway. Japan is particularly dependent on maritime routes for energy and trade.

The dispute therefore links national sovereignty with alliance credibility, resource access and the functioning of global commerce. That combination explains why relatively small shoals can generate consequences extending far beyond their physical size.

What are the key takeaways from the United States-Japan-Philippines South China Sea drills?

• The Armed Forces of the Philippines, Japan Maritime Self-Defense Force and United States Navy conducted a five-day Multilateral Maritime Cooperative Activity inside the Philippine exclusive economic zone from July 21 to July 25, 2026.
• The exercise involved anti-submarine warfare, maritime domain awareness, replenishment at sea, vertical replenishment and coordinated division tactics intended to strengthen communication and operational interoperability among the three participating countries.
• Participating assets included USS Santa Barbara, JS Yudachi, BRP Antonio Luna, BRP Malabrigo, a United States P-8A Poseidon and multiple Philippine fighter, surveillance and search-and-rescue aircraft.
• The exercise began after a confrontation at Second Thomas Shoal in which Philippine authorities said Chinese Coast Guard personnel struck Filipino sailors, while China accused the Philippine side of initiating the violence.
• Chinese Coast Guard ships also used water cannons against Philippine government vessels near Scarborough Shoal during the exercise, with Manila and Beijing issuing sharply conflicting accounts concerning responsibility and maritime jurisdiction.
• The Philippines relies on the 2016 arbitral decision that rejected the legal basis for China’s broad historic-rights claim, while China continues to reject the ruling and assert sovereignty across most of the South China Sea.
• The United States has repeatedly stated that its Mutual Defense Treaty with the Philippines applies to armed attacks against Philippine armed forces, public vessels and aircraft operating in the South China Sea.
• The expanded trilateral exercises may strengthen deterrence and crisis readiness, but the growing number of warships, coast guard vessels and aircraft also increases the possibility that a collision or confrontation could escalate rapidly.