India has successfully tested its K-4 Nuclear-Capable Ballistic Missile- Submarine Launched (SLBM) from the newly commissioned nuclear-powered submarine, INS Arighaat. The K-4 nuclear-capable ballistic missile, developed by the Defence Research and Development Organization (DRDO), can carry a 1-2 tonne payload over a range of 3,500 km.

Ahead of the test, Indian authorities issued a public area warning and a NOTAM for an intermediate-range missile launch, designating a 3,490 km flight corridor over the Bay of Bengal.

Measuring 10 meters in length and weighing 20 tonnes, the K-4 nuclear-capable ballistic missile has undergone at least 05 tests in recent years using submersible platforms.

INS Arighaat, the second submarine in the Arihant class, was inducted into the Indian Navy in August 2024 at Visakhapatnam. This Nuclear-Powered Submarine can carry 4 nos of K-4 nuclear-capable ballistic missiles.

Top 5 Facts About K-4 nuclear-capable ballistic missiles:

1. It is developed by DRDO (Defence Research and Development Organization, India)
2. It is a nuclear capable intermediate range submarine launched ballistic missile
3. Maximum Range is 3500 KM & Powered by Solid rocket propellant with a 2-stage solid rocket motor
4. It is the first Missile that activates India’s Nuclear Triad Capability
5. Guidance System: Inertial Navigation System with GPS/NAVIC Satellite Guidance

The successful K-4 nuclear-capable ballistic missile test massively shifts the strategic equation. With its 3,500 km range, an SSBN like INS Arighaat armed with K-4 nuclear-capable ballistic missile can strike critical targets across much of China, including Beijing, as well as anywhere in Pakistan, all while operating securely from protected zones in the northern Bay of Bengal.

This capability minimizes exposure to anti-submarine warfare (ASW) threats and improves survivability, a key element for maintaining credible deterrence under India’s no-first-use policy. The K-4’s extended range and deployment strengthen the reliability of India’s second-strike capability, a cornerstone of its nuclear doctrine of massive retaliation.

Development of a K-5 missile, with a range of 5,000 km, is also underway, aiming to fill the gap between regional and intercontinental strike capabilities. At the same time, the DRDO’s Advanced Naval Systems unit in Hyderabad is working on the K-6 SLBM as well, which will have a 6,000 km range and feature MIRV (multiple independently targetable reentry vehicle) technology.