On Tuesday, India test-fired the K-4, an intermediate-range ballistic missile with a range of 3,500 km, from the nuclear-powered submarine INS Arighaat in the Bay of Bengal. The test, conducted off the coast of Visakhapatnam, involved the 6,000-tonne INS Arighaat, operated by the tri-service strategic forces command.
While the defense ministry has not released an official statement, sources confirmed that the missile tested was the solid-fueled K-4, capable of carrying a two-tonne nuclear payload. This missile is crucial for strengthening the sea leg of India's nuclear weapons triad, enhancing the country's strategic capabilities. With this test, India joins a select group of nations possessing the capability to launch nuclear missiles from land, air, and sea.
A source stated that a thorough analysis will assess whether the test met all technical parameters and mission objectives, or if any shortcomings were revealed. Ballistic missiles, especially those launched from submarines, typically require multiple tests to achieve full operational status. The two-stage K-4 missile had undergone several trials from undersea platforms before being tested from INS Arighaat for the first time in November of last year.
INS Arighaat, India's second nuclear-powered submarine with nuclear-tipped ballistic missiles (SSBN), was commissioned on August 29 last year. Its predecessor, INS Arihant, which became fully operational in 2018, is only capable of carrying the shorter-range K-15 missiles with a range of 750 km. India is expected to commission its third SSBN, INS Aridhaman, in the first quarter of 2026, and a fourth in 2027-28, under the Advanced Technology Vessel (ATV) program. The INS Aridhaman and the fourth submarine will be slightly larger than the first two, with a displacement of 7,000 tonnes each compared to the 6,000 tonnes of the INS Arihant and INS Arighat. There are also plans to eventually build 13,500-tonne SSBNs with more powerful 190 MW pressurized light-water reactors.
The K-4 missile, designed to be launched from Arihant-class nuclear-powered submarines, has a range of approximately 3,500 km and can strike deep into enemy territory. It can carry both conventional and nuclear warheads, with a payload capacity of up to 2,000 kg, and utilizes a solid-fuel rocket motor, enhancing accuracy and reducing detection chances. The missile was tested from an underwater platform, simulating real-world conditions.
The successful test of the K-4 strengthens India's second-strike capability, which is critical for nuclear deterrence. With a range of approximately 3,500 kilometers and a payload capacity of up to 2,500 kilograms, the K-4 can cover strategic targets across Pakistan and significant portions of mainland China from patrol areas in the northern Indian Ocean. This allows India to maintain its ballistic missile submarines away from hostile shores, enhancing deterrence stability through survivability. This test marks a step in India's evolution as a sea-based deterrence state, with implications for regional and global security.
