The S-400’s performance during Operation Sindoor was exemplary, Russian ambassador Denis Alipov stated, highlighting a moment that has changed India’s air defence arithmetic.
Russia is scheduled to deliver all five S-400 Triumf regiments to India under the $5.43 billion deal signed in 2018 by 2026. Four regiments two battalions each of eight launchers are already operational, placed at strategic sites across Punjab, Rajasthan, and Gujarat. The last regiment, which is behind schedule due to the Russia–Ukraine conflict, will arrive next year. The purchase went ahead in anticipation of U.S. Countering America’s Adversaries Through Sanctions Act (CAATSA) sanctions, a policy that has in the past been used on China and Turkey for similar acquisitions.
The S-400, renamed in India as the Sudarshan Chakra, is a surface-to-air missile system with long detection ranges of up to 600 km and engagement ranges of up to 400 km. Its layered suite of missiles from the short-range 9M96E to the very-long-range 40N6 allows for simultaneous tracking and engagement of 36 airborne threats such as aircraft, drones, cruise missiles, and ballistic missiles. Mobile launchers and the ability for rapid redeployment provide battlefield versatility.
Operation Sindoor in May 2025 put this architecture to test in combat. In response to the April 22 Pahalgam civilian killings that took 26 lives, India conducted precision strikes against terrorist infrastructure in Pakistan and Pakistan-occupied Kashmir. Pakistan responded with missile and drone attacks, including the Fatah II ballistic missile touted an “S-400 destroyer” for its flat trajectory and 400 km range. One of the Fatah II missiles targeting New Delhi was downed 220 km to the west of Sirsa, breaking Pakistani belief in its system. The S-400’s missiles and radar batteries compelled several Pakistani strike missions to turn back or change direction, neutralizing both the drones and the incoming missiles.
This success on the battlefield has increased Indian interest in Russia’s S-500 Prometheus next-generation system. Developed to neutralize threats outside the range of the S-400, the S-500 has a detection range of ballistic targets at 2,000 km and airborne targets at 800 km, and is capable of intercepting ballistic missiles at distances of up to 600 km as well as targeting at altitudes near space (180–200 km). Its 77N6 hit-to-kill interceptors provide enhanced lethality against hypersonic glide vehicles, while jam-proof, multi-frequency radar provides tracking capability for stealth aircraft as well as for low Earth orbit satellites. The system can engage up to 10 targets simultaneously with a response time of just 3–4 seconds.
For India, the capabilities of the S-500 fill a vital gap: the lack of fifth-generation fighters like the AMCA, whose induction has been pushed back, and the tactical advantage Pakistan could accrue from its intended fleet of Chinese J-35A stealth aircraft. In such an environment, a high-altitude, long-range missile umbrella could function as an asymmetric counter, securing airspace against next-generation aerial attacks and even space-based weaponry.
Globally, the S-500 would place India in the league of very few nations operating defences for hypersonic and exo-atmospheric threats. Comparatively, U.S. systems such as THAAD and Patriot PAC-3 have already tested ballistic missile interception but with different altitude and range envelopes; Israel’s Iron Dome has superiority in short-range rocket defence but no strategic reach like that of the S-500; China’s HQ-9 series, however, powerful, falls short of the Prometheus in near-space combat capability.
India’s decision will hinge on balancing strategic need, cost, and geopolitical risk. As with the S-400, CAATSA sanctions remain a potential flashpoint. Yet the demonstrated combat performance of the Sudarshan Chakra and the emerging regional threat matrix suggests that New Delhi’s interest in the S-500 is not merely aspirational, but a calculated step in fortifying its multi-layered air defence grid for the next decade.
