The proliferation of nuclear-powered ballistic missile submarines (SSBNs) by India in the Indian Ocean Region (IOR) represents a significant development with far-reaching implications for the security architecture of South Asia. India’s nuclear submarine program is part of a broader strategy to enhance its naval capabilities in the IOR, aimed at countering China’s growing influence in the region.

India’s INS Arihant and INS Arighaat mark its leap into nuclear-powered maritime deterrence with SLBMs targeting Pakistan and beyond.

While the United States has recognized India as a net security provider in the IOR, with the intent of curbing China’s rise, the expansion of India’s nuclear submarine fleet raises critical security concerns for Pakistan and alters the region’s strategic balance. While Pakistan is already lagging behind India in terms of conventional military strength, landmass, and economic power, the growing maritime capabilities of India are likely to exacerbate Pakistan’s security dilemma.

India has docked two nuclear-powered SSBNs; INS Arihant and INS Arighaat. Commissioned in 2016, INS Arihant is armed with K-15 missiles with a target range of 750 km, while deploying in 2023, INS Arighaat is equipped with the more advanced Kalam series missile: K-4 with a projected range of 3500 km. These missiles can carry nuclear warheads. Just a few days ago, on 27 November India carried out a successful test of a K-4 submarine-launched ballistic missile (SLBM) from the INS-Arighaat.

With the successful launch of a K-4 missile (SLBM) from a nuclear submarine, India has demonstrated itself as a potential naval power in the region. It also underlines India’s persistent struggle to spread out its nuclear submarine fleet. Moreover, India is likely to commission its third SSBN, the INS Aridhaman by 2025. It will further augment India’s defense prowess, strategic autonomy, and deterrence against Pakistan. With the project of indigenization of defense technology, India’s maritime assets are increasing in the region.

India’s development of the K-4 SLBM, capable of carrying MIRV technology, underscores its advancing second-strike capability.

The K-15 missile when fired from the Bay of Bengal can hit Southern Pakistan, while the K-4 missile which is an intermediate-range ballistic missile can precisely target all of Pakistan and much of China. India is projected to have produced around 172 nuclear warheads, of which 24 are referred to its ballistic missile submarines as per a report published by the Bulletin of the Atomic Scientists. Given the fact, that India has demonstrably achieved second-strike capability and become a significant naval power in the region.

Moreover, with tangible progress in defense capabilities, India has conducted a successful trial of the Agni-5 missile, which is loaded with Multiple Independently Re-entry Vehicle (MIRV) technology. MIRV is the latest technology in the missile domain, with the ability to exact unprecedented damage on the enemy side. There is a high chance that K-4 SLBM will also be mated with MIRV technology, which will further strengthen India’s sea-based deterrence.

This evolving nuclear deterrence posture underscores India’s strategic intent to solidify its position as a major regional power while also intensifying security challenges for its neighbors, particularly Pakistan. Moreover, India also intends to build larger 13500-tonne SSBNs equipped with pressurized light water reactors (PLWRs) and Intercontinental ballistic missiles (ICBMs), to further strengthen its maritime posture.

Pakistan’s Babur-3 SLCM lacks credible second-strike capability due to operational limitations tied to diesel-electric submarines.

Similarly, India is building a multi-billion-dollar base designed to protect India’s growing fleet of nuclear submarines in a key area of the Indian Ocean. The new base, INS Varsha, has secret design features. Its location essentially allows for the underground docking of the submarines.

Pakistan’s security concerns regarding India’s SSBN program are well-founded. India’s development of a sea-based nuclear deterrent, through its SSBN fleet, significantly affects the strategic balance in South Asia. Presently, Pakistan does not possess nuclear-powered ballistic missile submarines, which further complicates its security posture.

In response to the threat posed by India’s INS Arihant, Pakistan has developed the Babur-3, a submarine-launched cruise missile (SLCM). This missile is a sea-based variant of Pakistan’s ground-based Babur-2 and can carry nuclear warheads, with an estimated range of 450 km.

Enhanced collaboration with China could help Pakistan build SSBNs to counter India’s growing naval dominance in the Indian Ocean.

Nonetheless, the Babur-3 missile has some operational constraints. First, it is stationed and fired from a Diesel-electric submarine or Air-independent Propulsion platform. Diesel-electric submarines are less efficient agile, and noisier which makes it vulnerable to the enemy’s first strike. Hence, Baber-3 with a diesel-electric submarine does not provide Pakistan with credible second-strike capability.

Therefore, Pakistan needs to focus on investing more in maritime force-building. China can help Pakistan in building nuclear-powered submarines (SSNs) and nuclear-powered ballistic missile submarines (SSBNs) to balance the Indian maritime force posture in the Indian Ocean region. Since the nuclear deterrence of Pakistan relies on ground-launched missiles and air power systems which are vulnerable to enemy attack, Pakistan needs to reassess its defense capabilities.

Disclaimer: The opinions expressed in this article are solely those of the author. They do not represent the views, beliefs, or policies of the Stratheia.