India has taken a significant step in fortifying its maritime nuclear deterrence with the launch of its fourth nuclear-powered ballistic missile submarine (SSBN), designated S4. This cutting-edge submarine, launched at the Ship Building Centre in Visakhapatnam, is more advanced than its predecessor, INS Arihant (S2), and marks a milestone in India’s naval defense capabilities.
India’s SSBN Program: Strengthening Nuclear Deterrence
India’s SSBN program, part of its Advanced Technology Vessel (ATV) initiative, is a cornerstone of the country’s strategy to strengthen its nuclear deterrence. The program began with INS Arihant, commissioned in August 2016 as India’s first SSBN, primarily functioning as a technology demonstrator. Since then, India has continued to expand its SSBN fleet, which now includes INS Arighaat (S3) and the recently launched S4, with the imminent INS Aridhman also under development. The addition of S4 demonstrates India’s commitment to maintaining a credible minimum deterrence (CMD) strategy by building a diversified and modern nuclear triad.
Enhanced Capabilities: S4 Submarine Specifications
The S4 submarine represents a notable advancement over its predecessors. While INS Arihant and INS Arighaat are both powered by an 83 MW pressurized light-water reactor and have a displacement of around 6,000 tonnes, the S4 is larger and features an upgraded reactor design, delivering improved power and operational capabilities. S4 is equipped to carry multiple K-4 submarine-launched ballistic missiles (SLBMs), with a strike range of 3,500 kilometers. This capability allows India to extend its undersea strike range, enhancing its ability to conduct submerged nuclear deterrence missions.
The K-4 Missile: Backbone of India’s Underwater Deterrent
The K-4 SLBM, tested successfully in 2020, is pivotal for India’s underwater nuclear deterrence. Capable of launching nuclear strikes while submerged, it significantly improves the survivability and strategic reach of India’s SSBN fleet. This will serve as India’s primary undersea deterrent until the development of an extended 5,000-kilometer-range SLBM, which will further increase India’s strike capacity and solidify its nuclear triad.
Nuclear Triad and India’s Deterrence Strategy
India achieved nuclear triad status in November 2018, completing its first deterrence patrol with INS Arihant. This accomplishment allows India to launch nuclear strikes from land, air, and sea, providing a full-spectrum deterrent capability. India’s nuclear doctrine is grounded in Credible Minimum Deterrence (CMD) and a No First Use (NFU) policy, pledging not to initiate nuclear conflict but reserving the right to retaliate with decisive force if attacked.
The S4’s introduction into India’s SSBN fleet enhances this triad, offering India strategic flexibility and increased security. It aligns with India’s commitment to regional stability and CMD, particularly in a complex security environment with nuclear-armed neighbors.
Future Plans and Strategic Expansion
Looking ahead, the Government of India has approved the construction of two indigenous nuclear attack submarines (SSNs), which differ from SSBNs in being hunter-killer submarines designed to track and neutralize adversary submarines and surface vessels. These SSNs will provide India with the agility to safeguard the Indo-Pacific region, complementing the current SSBN fleet and expanding its strategic footprint.
The launch of the S4 and India’s dedication to developing a robust SSN fleet reflect a strengthened national security strategy and a commitment to maintaining regional stability. As India moves closer to operationalizing the S4 and integrating advanced SSNs, its nuclear deterrence capabilities will play a vital role in safeguarding national interests and promoting peace in an increasingly dynamic security landscape.