India commissioned its third nuclear-powered ballistic missile submarine, INS Aridhaman, on April 3, 2026, according to a War on the Rocks report. This milestone allows New Delhi to reliably maintain at least one boomer on deterrent patrol at all times, completing the sea-based component of its nuclear triad.
The strategic shift enhances India's second-strike capability, complicating adversary calculations about a disarming first strike. With three submarines, the Indian Navy can rotate vessels between patrol, maintenance, and training cycles without leaving a gap in coverage — a posture analysts describe as true continuous-at-sea deterrence.
India has also demonstrated the ability to deploy multiple independently targetable reentry vehicles (MIRVs) from a single missile. Integrating this technology into sea-launched ballistic missiles would allow a single submarine to strike multiple targets, further guaranteeing unacceptable retaliatory damage. China and Pakistan, India's primary nuclear rivals, are expected to respond with enhanced surveillance and potential counter-deployments in the Indian Ocean.
The INS Aridhaman's induction follows a decades-long shipbuilding program aimed at closing the gap with China's larger submarine fleet. Budget figures for the submarine itself were not disclosed in the report, though India's overall naval modernization budget has seen steady increases in recent years.
Counter-argument: Maintaining continuous deterrent patrols requires not just hulls but a robust logistics chain, spare parts availability, and skilled crews — challenges that have historically plagued India's submarine force. An unexpected reactor issue or crew shortage could still create coverage gaps, undermining the strategic rationale.