India’s Nuclear Attack Submarine Program Officially Set in Motion

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In a landmark move for India’s maritime defence strategy, the Government of India has formally approved the initiation of the country’s long-delayed nuclear-powered attack submarine (SSN) program. At a recent meeting, the Cabinet Committee on Security (CCS) sanctioned funding for the construction of the first two SSNs under a broader plan to build a fleet of six indigenous nuclear attack submarines for the Indian Navy.

This development marks a transformative step in India’s naval modernisation, particularly as the country faces mounting strategic challenges across the Indian Ocean Region (IOR). With over 7,500 kilometers of coastline and expanding maritime responsibilities, India’s conventional submarine fleet has been stretched thin. The current diesel-electric submarines, while valuable, have limited endurance and operational range — constraints that SSNs are specifically designed to overcome.

Unlike nuclear-powered ballistic missile submarines (SSBNs) that serve as strategic deterrents with nuclear payloads, SSNs are tactical platforms capable of long-endurance patrols, aggressive anti-ship and anti-submarine warfare, and covert surveillance. These are critical in enforcing sea control and projecting power deep into contested waters.

India has prior experience with SSNs — both acquired through leases from Russia. The first INS Chakra, a Charlie-class submarine, served from 1987 to 1991, while the second Chakra, an Akula-class submarine, operated between 2011 and 2021. A third lease of another Akula-class submarine has been in discussion, but this time, India is taking the bold step of building its own from the ground up.

The planned Indian SSNs are expected to displace around 6,000 tonnes and will be powered by advanced pressurized water nuclear reactors (PWRs) — an upgrade over those used in the Arihant-class SSBNs. Each submarine will be outfitted with modern torpedoes, anti-ship, and land-attack cruise missiles, enabling them to engage a wide range of targets across multiple theatres of conflict.

The projected cost per SSN stands at ₹16,000 crore, underscoring both the complexity and strategic importance of this undertaking. Indian engineering conglomerate Larsen & Toubro (L&T), which led construction efforts on India’s Arihant-class SSBNs, will again be a central figure in building the SSN fleet, with support from the Bhabha Atomic Research Centre (BARC) and other national defence labs.

China’s increasing naval footprint, including regular SSN and SSK patrols in the Indian Ocean and its expanding fleet of nuclear submarines, has pushed Indian planners to re-evaluate their undersea strategy. Unlike conventional submarines that must surface frequently to recharge, SSNs can remain submerged for extended periods, granting them the ability to track enemy vessels undetected, conduct long-duration patrols, and launch strikes deep into enemy territory without being easily neutralized.

India’s existing submarine fleet, made up of aging Russian Kilo-class, German Type 209, and French Scorpene-class submarines, has performed well but remains limited in number and endurance. While six Scorpene-class boats have been built under Project 75, further plans under Project 75I to add six more advanced conventional submarines remain in limbo.

The SSN program, therefore, represents a strategic pivot — an embrace of next-generation naval capabilities that emphasize indigenous development, strategic deterrence, and long-range operational flexibility. It aligns closely with the national vision of Atmanirbhar Bharat (Self-Reliant India), aimed at reducing dependency on foreign platforms and cultivating sovereign defence technologies.

Importantly, the SSN program will catalyze innovation across multiple high-tech domains — including nuclear propulsion, stealth hull design, acoustic sensor systems, underwater communications, and missile integration. This technological momentum is expected to uplift India’s entire defence industrial base, fostering public-private collaboration, generating employment, and expanding R&D capacity in critical sectors.

SSNs also represent unmatched versatility. Whether it’s stalking enemy submarines, shadowing carrier strike groups, enforcing exclusion zones, or launching precision land strikes, SSNs are force multipliers. As stealthy hunters, they can operate in contested waters with minimal risk, holding adversaries at bay without needing surface support.

While India’s SSBN program has seen notable success with INS Arihant and INS Arighaat, the SSN fleet will serve a different and equally vital purpose — enabling active, peacetime and wartime operational control of maritime domains, especially in chokepoints and contested waters across the Indo-Pacific.

The approval of this project also comes amid a global trend where navies, including those of the U.S., China, France, and the UK, are investing heavily in undersea warfare. The significance of undersea dominance has never been higher, particularly in an era of evolving threats like long-range anti-ship missiles, hypersonic glide vehicles, and AI-enabled maritime surveillance systems.

India’s strategic choice to push ahead with its SSN fleet now, despite fiscal and logistical constraints, reflects the urgency of maintaining maritime superiority and responding credibly to regional threats. If executed with the requisite political will and industrial discipline, the SSN program will become a cornerstone of India’s defence strategy in the decades to come.

Written by Defence Expert