India Conducts Second Successful K-4 SLBM Test From Nuclear Submarine, Boosts Sea-Based Deterrence

India has taken another step in strengthening its sea-based nuclear deterrence with the successful test of the K-4 submarine-launched ballistic missile, capable of striking targets up to 3,500 km away.

The missile was launched from a nuclear-powered submarine in the Bay of Bengal, marking a key milestone in India's strategic weapons programme.

K-4 Missile Test Conducted From INS Arighaat

Defence sources confirmed that the K-4 missile was test-fired from INS Arighaat off the coast of Visakhapatnam. The launch was carried out under the operational command of the Strategic Forces Command. While the test was described as successful, the Ministry of Defence did not issue an official statement on the exercise.

Second Successful Launch Moves Missile Closer to Induction

This was the second confirmed test of the K-4 missile, following an earlier launch conducted last year from the same submarine. The repeated trials indicate that the missile system is nearing full operational readiness.

Developed by the Defence Research and Development Organisation, the solid-fuel K-4 is designed specifically to be deployed from India's nuclear-powered submarines, significantly enhancing the country's second-strike capability.

INS Arighaat Strengthens India's Nuclear Deterrence

Commissioned into the Indian Navy in August 2024, INS Arighaat is India's latest nuclear-powered submarine with a displacement of around 6,000 tonnes. The platform is capable of carrying K-4 missiles with a 3,500 km range, providing far greater reach compared to earlier systems. India's first nuclear submarine, INS Arihant, commissioned in 2016, was armed with K-15 missiles that had a much shorter range of about 750 km.

Part of India's Push to Match Global SLBM Capabilities

Earlier tests of the K-4 missile were conducted from submersible pontoons, but launches from an operational submarine represent a major leap towards deployment. Major powers such as the United States, Russia and China already operate submarine-launched ballistic missiles with ranges exceeding 5,000 km. In this context, the K-4 programme is viewed as a crucial element of India's effort to build a credible and survivable nuclear deterrent at sea.