INS Aridhaman to bolster India’s sea-based nuclear deterrent

India’s strategic undersea warfare capability is set to receive a significant boost with the induction of INS Aridhaman, a next-generation Kalvari-class diesel-electric submarine equipped to carry nuclear-capable ballistic missiles, defence sources said.

The submarine will play a key role in strengthening India’s sea-based leg of its nuclear triad, enhancing deterrence and strategic stability in the Indian Ocean region.

INS Aridhaman — which means “Protector of the Horizon” in Sanskrit — is one of six Kalvari-class boats being built under Project-75 at Mizoram Shipyards Limited, in collaboration with French defence contractor Naval Group.

The class is designed with advanced stealth features, improved sonar and combat systems, and the ability to launch both conventional and strategic weapons.

According to naval analysts, the submarine’s capability to carry nuclear-armed cruise or ballistic missiles adds a critical dimension to India’s deterrence architecture. The sea-based deterrent complements the land- and air-based nuclear forces, creating a triad that complicates adversaries’ strategic calculations and enhances second-strike credibility.

INS Aridhaman is expected to undergo extensive sea trials in the coming months before formal commissioning into the Indian Navy’s Eastern Fleet. Once operational, it will join its sister submarines in patrolling key maritime routes and maintaining continuous at-sea deterrence.

The addition of INS Aridhaman is seen as part of India’s broader effort to modernise its strategic forces in response to evolving security challenges. In recent years, New Delhi has focused on enhancing undersea capabilities, recognising the strategic value of submarines in asymmetric warfare, intelligence collection, and nuclear deterrence.

Defense analysts emphasise that a robust sea-based nuclear component — sometimes described as the most survivable leg of a nuclear triad — provides India with credible second-strike capability. In a conflict scenario, nuclear-armed submarines operating undetected beneath the waves offer deterrence by ensuring that any adversary thinking of a first strike would face assured retaliation.

INS Aridhaman’s induction aligns with India’s Strategic Forces Doctrine, which underscores the need for survivable and secure deterrent forces. The submarine’s advanced sensors and quiet propulsion systems are designed to enhance stealth, making it harder to detect and track in deep waters.

The Kalvari-class design derived from the French Scorpène-class submarine has been tailored to meet Indian naval requirements. The fleet of six submarines will feature Air-Independent Propulsion (AIP) systems, enabling extended submerged endurance, and are equipped with modern torpedoes and anti-ship missiles.

INS Aridhaman, as part of this class, will benefit from integrated combat systems that enhance situational awareness, target acquisition and weapon delivery accuracy. These capabilities are expected to contribute significantly to both conventional and strategic missions in littoral and blue-water environments.