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. 25/10/2024 2:50 PM
India recently launched its fourth nuclear-powered ballistic missile submarine (SSBN), designated S4, at the Ship Building Centre in Visakhapatnam. More advanced than its predecessor, INS Arihant (S2), the launch of S4 marks a significant milestone in strengthening India’s naval and strategic deterrence capabilities. But what does this development signify for India's overall defense strategy? And how does it fit into the broader context of India's evolving SSBN program and nuclear deterrent?
India’s SSBN (Sub-Surface Ballistic Nuclear) program is a cornerstone of its nuclear deterrence strategy, aimed at ensuring survivability and second-strike capability in the event of a nuclear attack. The program began with the commissioning of INS Arihant in August 2016 under the Advanced Technology Vessel program. This marked India's entry into the elite group of nations capable of operating nuclear-powered submarines that can carry nuclear-armed ballistic missiles.
Currently, India operates two SSBNs: INS Arihant and INS Arighaat (S3). These vessels serve as critical components of India's nuclear triad, allowing nuclear launches from sea, in addition to land and air-based options. The newly launched S4 submarine, with its technological advancements, is poised to further elevate India's strategic deterrence capabilities.
The newly launched S4 submarine boasts several key improvements over its predecessors. While INS Arihant has a displacement of 6,000 tonnes and is powered by an 83 MW pressurized light-water reactor using enriched uranium, the S4 features an enhanced reactor design and is significantly larger, providing increased capabilities. INS Arighaat, which follows INS Arihant in specifications, also includes technological upgrades, but the S4 represents a step forward in terms of both size and technological sophistication.
One of the major advancements of the S4 is its ability to carry multiple K-4 submarine-launched ballistic missiles (SLBMs), each with a range of 3,500 kilometers. This extended range bolsters India's undersea strike capabilities, further ensuring the survivability of its second-strike capability in the event of a nuclear conflict. The S4 is expected to enter service after completing sea trials for the third SSBN, INS Aridhman (S4*).
India's nuclear triad, achieved in November 2018 when INS Arihant completed its first deterrence patrol, is vital for maintaining a credible minimum deterrence (CMD) strategy. The triad allows India to launch nuclear weapons from land, air, and sea, thus ensuring that its nuclear deterrent remains secure even in the face of a surprise attack on one leg of the triad.
The addition of the S4 to the SSBN fleet further strengthens this triad. Submarine-based nuclear weapons provide a significant advantage due to their stealth and survivability. A submerged SSBN is much harder to detect and target, making it an ideal platform for second-strike capability, which is a key component of India's nuclear deterrence doctrine.
The K-4 submarine-launched ballistic missile (SLBM) is a crucial part of India's undersea nuclear deterrence. Successfully tested in 2020, the K-4 missile extends India's nuclear reach to 3,500 kilometers. The missile’s ability to be launched from a submerged SSBN enhances the survivability of India’s nuclear deterrent, allowing India to maintain strategic stability even in the face of evolving regional threats.
Until a more advanced SLBM with a range of 5,000 kilometers is developed, the K-4 will serve as the backbone of India’s underwater deterrent, providing the necessary range to strike deep into adversary territories from secure positions in the ocean.
India’s nuclear doctrine is based on the principles of credible minimum deterrence (CMD) and No First Use (NFU). Under this policy, India maintains that it will not initiate a nuclear strike but reserves the right to respond with massive retaliation if attacked first. This doctrine, formalized after the 1998 Pokhran-II nuclear tests, aims to ensure that India’s nuclear weapons are purely defensive and deterrent in nature.
The SSBN program, including the S4 and the K-4 SLBMs, plays a crucial role in implementing this doctrine. By ensuring that India has a secure second-strike capability, the SSBN fleet reinforces India’s deterrent posture, making any potential adversary think twice before launching a nuclear attack.
The launch of the S4 is just one part of India’s broader naval modernization program. Recently, the Government of India approved the construction of two indigenous nuclear attack submarines (SSNs). Unlike SSBNs, which are primarily designed for deterrence, SSNs are hunter-killer submarines meant to track and neutralize enemy submarines and surface ships. These SSNs will complement India’s SSBN fleet, enhancing the country’s ability to secure its maritime interests, particularly in the strategically significant Indo-Pacific region.
The development of these advanced submarines, alongside the SSBNs like the S4, signals India's commitment to bolstering its naval capabilities and ensuring the safety of its sea-based nuclear deterrent.
The launch of the S4 marks a major milestone in India’s SSBN program and its nuclear deterrent capabilities. As India continues to modernize its submarine fleet and expand its underwater nuclear strike capabilities, it is solidifying its position as a formidable maritime and nuclear power. The addition of advanced SSBNs like the S4, armed with the K-4 missile, ensures that India’s nuclear deterrent remains credible, robust, and survivable.
As India faces evolving regional security challenges, particularly in the Indo-Pacific, these advancements reflect a strategic commitment to national security and regional stability.
