With so much media focus in recent months on the war in Iran, it’s no surprise that Undersecretary of War for Policy Elbridge Colby’s speech in Manila received so little coverage. That means very few know what the U.S. and its allies are doing to deter China from launching any hostilities of its own.

In April, Filipino marines undertook one of the most expansive iterations of Balikatan, the annual bilateral U.S. and Philippines military exercise. They took part in simulated firing of the BrahMos anti-ship missile during the joint maritime strike phase of the exercise. The BrahMos is an Indian missile, and while India was not a participant in Balikatan, it joined as an observer. The image of a U.S.-Philippine drill with an Indian weapons platform aptly captures India’s role in the South China Sea.

India is not explicitly present and may never put boots on the ground, and yet its presence is felt in how it strengthens the deterrence of Southeast Asian partners through hardware, intel sharing, and strategic diversification. This is not necessarily a case of policy alignment but of strategic convergence: India’s pursuit of its own interests produces outcomes that complement Washington’s regional objectives.

Washington’s strategy in the first island chain rests on a strategy of denial by making it too costly for China to strike against a partner nation. The Trump administration has emphasized burden sharing, pushing allies and partners do their part in ensuring that they can defend themselves. This was captured best and most recently by Elbridge Colby’s speech. He not only spoke about the importance of maintaining a favorable balance of power in the Indo-Pacific but also how partners are expected to do their part.

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“When we ask our allies and partners to step up, to invest more in their own defense,” he said, “we are not signaling abandonment.” Colby argued that deterrence along the first island chain cannot rest on American power alone but must also rely on capable partners able to defend their own territory.

The Philippines has been doing its part, despite a rather small budget of approximately $6.12 in 2024 and $6.7 billion in the proposed 2027 budget—some of its highest figures to date. Manila also adopted Comprehensive Archipelagic Defense Concept in 2024 to focus on territorial and maritime defense. And the Self Reliant Defense Posture Law hopes to build indigenous defense capabilities, reinforced by the Horizon I, II, and III plans.

India is playing its own role albeit for its own interests of expanding defense exports, deepening its Act East Policy, and perhaps even hedging against China—a known challenge for India as much as it is for the United States and the Philippines. India is doing so through three levers: hardware, intel sharing, and enabling a strategic diversification strategy; all of which allow Philippines to burden share and reinforce denial strategies.

Regarding hardware, India sold to the Philippines three shore-based batteries for $375 million in 2022. India even offered a $100 million line of credit for the sale, though Manila decided to finance it from its defense appropriations. The batteries arrived on time in April 2024 and the first became operational in November in Zambales (in West Luzon) under the Marine Corps coastal defense regiment, providing a strike capability of 290 km that reaches Scarborough Shoal. India has since also offered extended range variants of 400 km with future batteries reaching up to the Spratlys when deployed from Palawan.

Recently the Philippines Ambassador to India Ignacio remarked how the BrahMos missiles Manila imported from New Delhi are a game changer and provide the Philippines with “real credible deterrence” as territorial challenges continue to rise in the South China Sea. India has also offered Akash surface to air missiles, Tejas LCA fighter jets, helicopters, and submarines and naval vessels. The sale of these platforms is commercially useful to India, but its second-order effect is also to strengthen the same maritime denial architecture Washington is pursuing in the region.

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Regarding intel, India invited the Philippines to the Information Fusion Center for the Indian Ocean Region (IFC-IOR) in 2025. The IFC-IOR is India’s maritime domain awareness hub which tracks activity in the Indian ocean region. The move builds on a 2023 coastal guard agreement and white shipping arrangement where the two navies are already collaborating on information sharing, maritime training, exchanges, joint search and rescue operations, and more. Greater maritime domain awareness improves Manila's ability to identify, track, and respond to Chinese activity, complementing the strike capabilities India is helping provide.

Last year, India and the Philippines also had their warships conduct their first joint maritime activity inside the Philippine exclusive zone and the South China Sea. Notably, Chinese vessels were shadowing them during the joint sail. India has also publicly backed Manila’s position in the South China Sea including the 2016 arbitral award in Philippines favor which China has ignored by continuing to extend its territorial claims through artificial islands and the nine dash line.

There are limitations. India is highly unlikely to ever put boots on the ground for the Philippines, but this may actually matter less. By providing strategic diversification, India strengthens the Philippine’s deterrence, making regional balancing look less like simply joining an American bloc. And that is the paradox here: the same strategic autonomy that limits how far India will pursue formal alliances also increases the value of what it does do.

Because New Delhi is neither a U.S. nor Philippine treaty ally, its cooperation is harder to portray simply as an extension of American alliance politics. By pursuing its own interests, India is in the process also reinforcing American interests.