S-400: Why India is buying more fighter-jet hunter ‘Sudarshan Chakra’ that gave Pakistani Air Force sleepless nights

India is set to bolster its air defence network with a major purchase of missiles worth around Rs 10,000 crore from Russia for its S-400 air defence system. The decision follows reports that the system successfully shot down six to seven Pakistani fighter and reconnaissance aircraft during Operation Sindoor.

"The Indian Air Force is looking to buy the missiles in significant numbers to further bolster its air defence capabilities. The discussions with the Russian side are already on in this regard," to further enhance its long-range strike and interception capabilities, defence sources told ANI.

According to the report, the defence ministry is expected to consider the IAF’s proposal at the upcoming Defence Acquisition Council meeting on October 23.


India signed a deal with Russia in 2018 to acquire five S-400 squadrons. Three have already been delivered on time, but the Russia-Ukraine war delayed the delivery of the fourth unit.

India has requested Moscow to expedite the remaining deliveries and is also exploring the possibility of adding more S-400 and even S-500 systems in the future.

Alongside the missile purchase, India and Russia are also holding talks on acquiring new air-to-air missiles to strengthen India’s beyond-visual-range capabilities. The two sides are additionally working on upgrading the BrahMos supersonic cruise missile and its next-generation variants.

What is S-400 Sudarshan Chakra?

The S-400, dubbed "Sudarshan Chakra" in India, is the Indian designation for the Russian-made S-400 Triumf air defence missile system—one of the world’s most advanced long-range surface-to-air missile systems.

Named after Lord Vishnu’s legendary weapon from the Mahabharata, the title reflects precision, speed, and deadly accuracy, mirroring the system’s real-world performance.

Developed by Russia’s Almaz-Antey, the S-400 can engage a wide range of aerial threats, including aircraft, drones, and ballistic missiles, at distances of up to 400 km, while detecting targets as far as 600 km away.

How S-400s were used during Operation Sindoor

During the four-day Operation Sindoor, the S-400 system reportedly shot down five to six Pakistani fighter jets and a spy plane over 300 km inside Pakistan—a feat the IAF has called a “game-changer,” effectively thwarting Islamabad’s attempt to target military installations.

With Russian President Vladimir Putin expected to visit India in December, the two countries are likely to prioritize deepening defence cooperation and expanding joint military hardware development, strengthening a partnership that remains central to India’s air power and strategic deterrence.