India has successfully conducted a significant test of the K-4 submarine-launched ballistic missile (SLBM), a crucial development in enhancing its sea-based nuclear strike capability. The test was executed from the nuclear-powered submarine INS Arighaat in the Bay of Bengal near Visakhapatnam.
The K-4 missile, designed to reach targets up to 3,500 kilometers away, bolsters India’s undersea nuclear deterrence, completing an essential aspect of the country’s nuclear triad, which encompasses the delivery of nuclear weapons via land, air, and sea. This advancement positions India among a limited group of nations equipped with operational submarine-launched nuclear missile capabilities.
Commissioned into the Indian Navy on August 29, 2024, the K-4 can carry a nuclear warhead weighing 2.5 tons and is deployable from Arihant-class nuclear submarines. The missile is derived from the Agni-III ballistic missile, specifically modified for underwater launches. Its design includes an innovative mechanism that enables it to eject from a submarine launch silo, break through the surface of the ocean, and ignite its engine for powered flight—an advanced technology possessed by only a few nations globally.
Defence analysts consider the K-4 to be the stealthiest component of India’s nuclear triad. Ballistic missile submarines are engineered for prolonged silent operation during deterrence patrols, allowing them to remain concealed in vast ocean expanses while ensuring a credible second-strike capability.
Furthermore, the K-series of missiles is named after A P J Abdul Kalam, honoring his influential role in India’s Integrated Guided Missile Development Programme (IGMDP).
This successful test reflects India’s increasing strategic sophistication, its indigenous missile development capabilities, and a steadfast commitment to upholding a credible minimum deterrence posture amid a complex regional security landscape.
