New Delhi/Islamabad: India is pushing its nuclear deterrence strategy deep into the waters of the Indian Ocean, preparing to blunt any aggression from China or Pakistan. What unsettles Islamabad most is not just India’s advances in naval power but the readiness of New Delhi to maintain an uninterrupted nuclear strike capability at sea.
Reports in the Pakistani press, including a long feature in The Tribune, suggest that Indian deployments in the Indian Ocean and the Bay of Bengal are being closely tracked. The report points to growing unease in Pakistan’s defense circles, where experts believe India has now centered its strategy around the Continuous at Sea Deterrence (CASD).
This concept requires that at least one nuclear ballistic missile submarine (SSBN) remains on patrol at all times. The goal is to ensure a guaranteed second strike, leaving no room for hesitation in the event of a nuclear attack.
Expanding India’s Undersea Nuclear Arsenal
Since the commissioning of INS Arihant in 2016 and the induction of INS Arighat in 2024, India has accelerated its nuclear submarine programme. Trials for the S-4 and S-4 SSBNs are underway, while work has begun on the S-5 class, massive 13,500-ton submarines that will anchor India’s long-term sea-based deterrence.
The submarines are armed with India’s formidable K-series of ballistic missiles. The K-15 (with a range of 750-1,500 km) is already operational. The K-4 (3,500-4,000 km) has been tested successfully.
In development are the K-5, expected to exceed 5,000 km with Multiple Independently Targetable Re-entry Vehicles (MIRVs), and the K-6, projected to carry hypersonic capabilities with ranges approaching 8,000 km. Each missile is designed to ensure a credible second strike, reinforcing India’s sea-based nuclear shield.
Pakistani analysts argue that New Delhi has shifted from a defensive posture to an assertive doctrine that resembles Cold War-era Soviet strategies, building hardened assets at sea, preparing for survival and guaranteeing retaliation. In their words, India has started turning the Indian Ocean into a “nuclear fortress”.
The Geography Advantage
Rehman, in the book, highlights that geography favors India’s nuclear submarines. The Bay of Bengal, unlike the crowded Arabian Sea, provides discreet maneuvering space for SSBNs. This advantage, he argues, enhances India’s survivability and complicates enemy tracking efforts.
India is also constructing an underground nuclear submarine base under Project Varsha near Visakhapatnam. Designed as a concealed facility, it will provide secure berthing for nuclear submarines and help maintain constant deterrence at sea.
The Larger Plan
Strategists believe India aims to build 10 to 12 nuclear submarines, including both SSBNs and nuclear-powered attack submarines (SSNs). The intention is to prepare for simultaneous challenges from both China and Pakistan.
This buildup is not going unnoticed in Islamabad. Pakistani analysts caution that such expansion may fuel a sharper regional arms race. Some argue that Pakistan’s best bet lies in advancing anti-submarine warfare capabilities. Others suggest exploring new nuclear options of its own.
At the same time, there are voices recommending the establishment of a naval hotline between India and Pakistan, modeled on the Cold War-era communication channels between the United States and the Soviet Union, to prevent accidental escalation.
A Shifting Balance
The Indian Ocean is no longer only a busy trade route. It is fast becoming the theater of an evolving nuclear rivalry. For India, the doctrine of constant readiness means security against surprise.
For Pakistan, it represents a challenge that demands answers on both military and diplomatic fronts.