India successfully tests K-4 nuclear missile, strengthens maritime nuclear triad

New Delhi (The Uttam Hindu): India successfully test-fired a stealthy submarine-launched ballistic missile (SLBM) on December 23, 2025. The test took place in the Bay of Bengal. It is reported to be a test of the nuclear-capable K-4 missile, launched from an Arihant-class nuclear submarine.

No official announcement was made in advance of this crucial test. Furthermore, a NOTAM (Notice to Airmen) was not issued to maintain secrecy. It is claimed that this was done because of the potential presence of Chinese surveillance vessels around the test area.

According to defense experts, this successful test further strengthens India's sea-based nuclear triad. It bolsters India's 'second strike' capability, ensuring effective retaliation even after an enemy's first nuclear attack. The K-4 missile is an indigenous K-series advanced ballistic missile developed by the Defense Research and Development Organization (DRDO). It is specifically designed for the Arihant-class nuclear submarines.

The missile has a range of approximately 3,500 kilometers. Its length is approximately 12 meters and its diameter is approximately 1.3 meters. The missile weighs between 17 and 20 tons, and it is capable of carrying a payload of approximately 2 tons.

The K-4 missile features cold launch technology for underwater launch. Furthermore, it is capable of 3D maneuvering and the ability to evade ballistic missile defense systems. Defense experts believe that this successful test of the K-4 missile is a clear indication of India's strategic strength and self-reliant defense capabilities.