U.S. and Indian Navies Enhance Anti-Submarine Capabilities Amid Rising Chinese Naval Power

The United States and India have conducted a joint anti-submarine warfare training exercise in the Indian Ocean, specifically near Diego Garcia, from October 22 to 28, 2025. This exercise involved U.S. Navy's P-8A Poseidon aircraft and Indian Navy's P-8I aircraft, focusing on enhancing operational interoperability between the two navies. The training aimed to bolster maritime domain awareness and refine anti-submarine warfare capabilities, reflecting a strategic partnership rooted in shared democratic values and a commitment to regional security.

NewsweekU.S. and Indian Navy aircraft conduct joint anti-submarine training in Indian Ocean near Diego GarciaU.S., Indian navies conduct bilateral training near Diego Garcia

China's naval expansion has prompted the U.S. and its allies to strengthen their maritime defenses. With a fleet exceeding 370 vessels, including 12 nuclear-powered and 48 diesel-powered submarines, China is increasing its military presence in the western Pacific and Indian Ocean. In response, the U.S. has been enhancing its capabilities and those of its Indo-Pacific allies, including India, through the sale of Boeing P-8 Poseidon aircraft, which are designed for anti-submarine and maritime surveillance operations.

NewsweekU.S. and Indian Navy aircraft conduct joint anti-submarine training in Indian Ocean near Diego GarciaU.S., Indian navies conduct bilateral training near Diego Garcia

U.S. Navy Captain Rodney Erler, commodore of Commander Task Force 72, emphasized the importance of maritime domain awareness, stating, “By working with our allies and partners, we increase our shared maritime awareness to ensure a free and open Indo-Pacific.” Following a meeting in February, U.S. President Donald Trump and Indian Prime Minister Narendra Modi expressed expectations for India to procure six additional P-8I aircraft to enhance its surveillance capabilities in the Indian Ocean.

U.S. and Indian Navy aircraft conduct joint anti-submarine training in Indian Ocean near Diego Garcia

While the U.S.-India partnership is framed as a response to Chinese aggression, some analysts argue that such military exercises could escalate tensions in the region. Critics suggest that increased military presence may provoke China and complicate diplomatic relations, potentially leading to an arms race in the Indo-Pacific.

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The timeline for India to complete its order of additional P-8I aircraft remains uncertain, while China continues to expand its military activities in the Indian Ocean. The ongoing collaboration between the U.S. and India is expected to evolve, with future exercises likely focusing on enhancing joint operational capabilities and addressing emerging maritime threats.

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• “Our P-8A crews were proud to fly alongside our Indian partners in this combined detachment,” — Captain Rodney Erler, U.S. Navy

U.S., Indian navies conduct bilateral training near Diego Garcia

• “The U.S.-India strategic partnership is founded on shared values including a commitment to democracy and upholding security, freedom, and prosperity.” — U.S. Seventh Fleet Press Release

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• “Despite the ongoing retirement of older hulls, the [People's Liberation Army Navy]'s submarine force is expected to grow to 65 units by 2025 and 80 units by 2035 due to an expansion of submarine construction capacity.” — Pentagon Chinese Military Power Report 2024

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This joint exercise underscores the strategic importance of U.S.-India cooperation in countering the growing naval capabilities of China, while also highlighting the complexities of regional security dynamics in the Indo-Pacific.

U.S. and Indian Navy aircraft conduct joint anti-submarine training in Indian Ocean near Diego Garcia