Why India is investing in two Nuclear Attack Submarines (SSNs)



In October 2024, the Cabinet Committee on Security approved the construction of two nuclear-powered attack submarines (SSNs) for the Indian Navy, allocating a budget of ₹45,000 crore for the project.

India has previously developed and commissioned two nuclear-powered ballistic missile submarines (SSBNs): INS Arihant in 2016 and INS Arighat in 2024. A third SSBN, codenamed S4, is currently under construction and is expected to be operational by 2025. This new vessel is anticipated to be larger than its predecessors.

Both SSBNs and SSNs are nuclear-powered vessels but serve different purposes. SSBNs are primarily used to launch long-range missiles, whereas SSNs are designed for offensive operations, such as engaging close-range threats. The acronyms SSN and SSBN stand for Submersible Ship Nuclear and Submersible Ship Ballistic Missile Nuclear, respectively.

To gain operational experience with SSNs, India has leased two such submarines from Russia in the past, both named INS Chakra. The timeline for the delivery of India's indigenously built SSNs remains uncertain, but estimates suggest it could take approximately a decade.

Nuclear submarines typically have a lifespan exceeding 30 years. While INS Arihant featured about 30% indigenous content, INS Arighat improved this figure to 60%. It is expected that the first SSN will achieve an even higher level of indigenous development.





India has also initiated work on Project Varsha, a strategic naval base designed to support a fleet of over 12 nuclear-powered submarines. Situated along the eastern coast by the Bay of Bengal, the base features an advanced underground docking complex, including tunnels likely intended to serve as submarine pens. This facility offers protection against aerial threats and surveillance while providing essential support for nuclear engineering. Above ground, additional piers are being constructed to accommodate a range of surface vessels, enhancing the base’s versatility.



One of Project Varsha’s key advantages is its ability to allow India’s nuclear submarines to deploy into the Bay of Bengal undetected by satellites or aircraft. Its location, on the western edge of the Bay of Bengal, is strategically significant, given the area’s trade routes, which carry approximately 30% of global commodities, and the Strait of Malacca, through which 80% of China’s oil imports pass.

The project also serves as a countermeasure to the growing presence of the Chinese Navy in regional ports, including those in Myanmar, Bangladesh, and Sri Lanka, which China has helped develop.



India’s second SSBN, INS Arighat, can carry four ballistic missiles with a range of up to 2,000 miles, potentially targeting most of China, including its Hainan naval base. While China operates 12 nuclear submarines, the geographical challenges of reaching the Bay of Bengal provide India an advantage. Conventional diesel-powered submarines could further bolster India’s defense by countering Chinese nuclear submarines in the region.

By accelerating its naval capabilities and preparedness, India aims to uphold a rules-based maritime order, ensuring its strategic interests are safeguarded against external threats.



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