India’s nuclear-powered ballistic missile submarine program has reached a decisive stage, transforming from a symbolic deterrent into a continuous, survivable capability. The essence of nuclear deterrence lies not in the weapon that inflicts the greatest destruction, but in the one that cannot be eliminated in a first strike.

Submarines running silent beneath the Indian Ocean embody this principle, ensuring that any adversary contemplating aggression must reckon with the certainty of retaliation.

The Advanced Technology Vessel project, initiated decades ago under strict secrecy, has now delivered tangible results. INS Arihant, commissioned in 2016, marked India’s entry into the exclusive club of nations capable of building and operating ballistic missile submarines.

Its successor, INS Arighaat, commissioned in 2024, demonstrated India’s ability to launch the K-4 intermediate-range ballistic missile from submerged positions, extending deterrence to China’s eastern seaboard.

The forthcoming INS Aridhaman represents a significant leap in capability. Unlike its predecessors, which carry four missile tubes, Aridhaman is equipped with eight, doubling its firepower. It can host up to 24 K-15 short-range missiles, eight K-4 intermediate-range missiles, or a mix, and is designed to accommodate the future K-5 missile. This flexibility ensures India’s deterrent remains credible against evolving threats.

A fourth vessel, INS Arisudan (S4 star or asterisk variant to distinguish it as an improved or final iteration of the class), has already begun sea trials and is expected to join the fleet by 2027. With four SSBNs in different phases of deployment, India will achieve a continuous at-sea deterrent, a milestone reached by only a handful of nations. This ensures that at any given time, at least one submarine remains undetectable and ready to respond.

The strategic backdrop is stark. China’s submarine fleet is projected to reach 80 vessels by 2035, while Pakistan is acquiring eight Yuan-class submarines from China. India’s SSBN fleet is being built as a direct counter to this two-front maritime challenge, ensuring that its nuclear deterrent remains invisible, survivable, and certain in its response.

The names of these submarines are not chosen lightly. Arihant, Arighaat, Aridhaman, and Arisudan symbolise India’s intent: a deterrent that is unseen, unyielding, and unwavering. For China and Pakistan, the message is clear—India’s nuclear shield beneath the Indian Ocean is no longer aspirational, but operational.

Agencies