India Launches Fourth Nuclear Ballistic Missile Submarine to Strengthen Sea-Based Deterrence
India quietly launched its fourth nuclear-powered ballistic missile submarine (SSBN), codenamed S4, on October 16, at the Ship Building Center in Visakhapatnam, signaling a significant enhancement in the country’s sea-based nuclear deterrence capabilities. The launch comes at a time when India is facing strategic challenges, including an ongoing diplomatic standoff with Canada and heightened activity from China in the Indo-Pacific.
A day before the launch, Defence Minister Rajnath Singh inaugurated a Very Low Frequency (VLF) Naval Station in the Damagundam forest area of Telangana. This station will enable command, control, and communications with the Indian Navy’s strategic assets, further bolstering India’s naval strength.
S4* is the last of its class of Arihant-class submarines, featuring a significant 75% indigenous content. The vessel is equipped with advanced K-4 nuclear ballistic missiles, which have a range of 3,500 km, capable of being launched vertically. Unlike the first of its class, INS Arihant, which carries the 750 km-range K-15 nuclear missiles, all subsequent vessels have been upgraded to feature only K-4 ballistic missiles, offering greater strike capabilities.
While the Indian government maintains a strategic silence on matters related to nuclear deterrence, the launch of S4* underscores the country’s commitment to fortifying its maritime security and deterring adversaries like China and Pakistan. The S4* follows the commissioning of the second SSBN, INS Arighaat, in August 2024, and precedes the commissioning of the third, INS Aridhaman, expected in 2025.
India’s focus on nuclear deterrence through sea-based platforms has gained priority over the development of a third aircraft carrier, given the vulnerability of carriers to long-range missile systems like China’s Dong Feng-21 and Dong Feng-26. With the ability to patrol the deep seas for extended periods, SSBNs offer a more secure and survivable nuclear deterrence option, constrained only by crew endurance, food supplies, and maintenance needs.
In line with the Modi government’s push to counter growing Chinese influence in the Indo-Pacific, the Cabinet Committee on Security recently approved the construction of two more nuclear-powered attack submarines. This decision aligns with India’s broader strategy to enhance its maritime defense against the increasing presence of the Chinese People’s Liberation Army Navy (PLAN) in the Indian Ocean Region (IOR).
India’s naval expansion also includes conventional submarine capabilities, with the commissioning of INS Vagsheer, the sixth diesel-powered Kalvari-class attack submarine, scheduled for December 2024. Additionally, the Indian government plans to construct three more advanced diesel attack submarines in collaboration with the French Naval Group at Mazagon Dockyards.
With an average of 10-11 Chinese warships patrolling the Indian Ocean every month and increased carrier-based long-range patrols expected in the near future, India’s strategic submarine fleet will play a critical role in securing its maritime borders and maintaining a dominant presence in the IOR.