India’s strategic nuclear arsenal took a bold leap forward with the first operational trial of a new submarine-launched ballistic missile, setting the stage for intensified rivalry with China and Pakistan in the Indian Ocean.
Last month, Indian Research Defence Wing (IDRW) reported that the INS Arihant, India’s first nuclear-powered ballistic missile submarine (SSBN), successfully tested the K-4 submarine-launched ballistic missile (SLBM).
The K-4 SLBM has a range of approximately 3,500 kilometers and represents a substantial upgrade over the K-15 missile, which has a range of only 750 kilometers. The IDRW report notes the trial marked a crucial step in integrating long-range SLBMs into India’s underwater strategic forces, enhancing the nation’s nuclear second-strike capability.
The K-4’s tests were conducted from submerged platforms, ensuring the missile’s effectiveness in realistic underwater launch scenarios, the IDRW report said. The successful trial underscores India’s commitment to maintaining a credible minimum deterrent while adhering to its no-first-use nuclear doctrine.
The K-5 SLBM, which is under development and has a range of over 5,000 kilometers, will further bolster India’s strategic capabilities.
In a September 2024 article for the Bulletin of Atomic Scientists, Hans Kristensen and other writers mention that the K-4’s capabilities are similar to those of the Agni-III intermediate-range ballistic missile (IRBM).
Kristensen and others say that India’s Defense Research and Development Organization (DRDO) claims the K-4 reaches “near zero circular error probability,” although they view that statement skeptically. They assess that the K-4 can hit all of Pakistan and most of China from protected bastions in the northern Bay of Bengal.
They write India’s SSBNs have launch tubes that carry one K-4 or three K-15 SLBMs. While they note rumors and speculation that the K-4 SLBM has multiple independently targetable re-entry vehicle (MIRV) warheads, this seems unlikely, given the missile’s limited capability.
However, that may change soon. In March 2024, Asia Times reported that India had successfully conducted its first flight test of the Agni-5 missile equipped with MIRV technology, marking a significant advancement in its strategic defense capabilities.
The test, carried out on Abdul Kalam Island in the Bay of Bengal, positions India among the elite nations with MIRV technology, including the US, UK, France, China, Russia and Pakistan.
Integrating MIRV technology enhances India’s second-strike capability, complicating adversaries’ missile defense strategies and reinforcing its no-first-use nuclear policy.
Further, Kristensen and others mention that senior Indian defense officials have stated that the DRDO is planning to develop a 5,000-kilometer-range SLBM based on the land-based Agni-V. This would enable Indian submarines to strike targets across Asia as well as various regions of Africa, Europe and the Indo-Pacific area, including the South China Sea.
Debak Das mentions in an April 2024 Bulletin of Atomic Scientists article that India’s sea-based nuclear arsenal, possibly equipped with MIRV SLBMs, will be the cornerstone of its second-strike capability and could seek to nullify China’s recent advancements in missile defense. He notes that MIRV-ed SLBMs will bolster the Indian Navy’s “continuous at-sea deterrence” capability, ensuring survivable nuclear force during a first strike.
China is unlikely to ignore such developments. In June 2024, Asia Times mentioned China’s growing naval presence in the Indian Ocean.
China’s potential utilization of its economic influence to secure base access at Gwadar in Pakistan and Hambantota in Sri Lanka, thereby strengthening its sole overseas military installation in Djibouti, could contest India’s supremacy in the Indian Ocean and heighten India’s concerns regarding encirclement.
While China’s base in Djibouti can facilitate its naval operations in the Indian Ocean, it is situated at the terminus of fragile supply lines, isolated and operationally constrained due to the lack of mutual support from other Chinese military installations in the Indian Ocean.
However, China’s dual-use commercial facilities at Gwadar and Hambantota have emerged as significant nodes for its naval operations.
Due to its geographic location, military significance and the involvement of a Chinese port operator, Gwadar has the potential to serve as a long-term rest and replenishment site for China’s People’s Liberation Army – Navy (PLA-N).
Further, certain factions within the PLA perceive Chinese access to the Gwadar base as effectively secured, with one PLA officer reportedly remarking, “The food is already on the plate; we’ll eat it whenever we want to.”
Hambantota is likely to become China’s next military base in the Indian Ocean. China has direct control of the facility, constituting its most significant port investment overseas.
From a military perspective, Gwadar and Hambantota can facilitate a sustained Chinese naval presence in the Indian Ocean, potentially threatening India’s sea-based nuclear deterrent.
However, the US may also factor in this negative Indian Ocean feedback loop. In a May 2024 report for the National Bureau of Asian Research (NBR), Rajeswari Rajagopalan mentions that India’s nuclear program has been driven more by threats from Pakistan than China.
Rajagopalan says that China’s accelerated modernization of its nuclear forces—marked by the development of long-range, land-based missiles and a potential arsenal expansion to thousands of warheads—has raised alarm in India.
She states this growth threatens India’s doctrine of minimum deterrence and could pressure India to reconsider its no-first-use policy, especially as China’s nuclear strategy moves toward parity with the US as the latter modernizes its nuclear arsenal.
She mentions these implications extend to border disputes, where a more assertive Chinese nuclear posture might encourage China to escalate conventional conflicts with India, such as their ongoing border dispute in the Himalayas.