India’s defence strategy has changed considerably over the years, particularly with the addition of advanced missile systems capable of addressing various types of aerial threats. Among the most notable additions to its air defence capability is the Russian-made S-400 Triumf, known in India as the “Sudarshan Chakra.” This long-range surface-to-air missile system has played a central role in strengthening India’s military preparedness against both regional and strategic threats.
India’s acquisition of the S-400 system in 2018 marked a major step forward in securing its skies, especially against high-speed missiles, fighter jets, drones, and even some ballistic projectiles. As tensions in South Asia continue to rise, the operational deployment of the S-400 has shown its value, particularly during the May 2025 India–Pakistan conflict, where it successfully intercepted several incoming aerial threats.
The S-400 missile defence system is an advanced piece of military technology developed by Russia’s Almaz Central Design Bureau in the late 1980s and brought into service by the Russian military in 2007. It was designed to counter developments in Western air defence systems, particularly the American-made MIM-104 Patriot.
The S-400 system was built as a successor to older platforms like the S-200 and S-300, and it improves upon them in both detection capability and engagement range. In India, the system has been given the title “Sudarshan Chakra,” drawing from Indian mythology where it represents a powerful and precise weapon capable of defeating evil. This symbolic title aligns with the actual role of the S-400 system in national defence: to act swiftly and with accuracy against airborne intrusions.
The S-400 missile system was developed by Russia to address evolving threats in modern air combat. It consists of several major components including the launcher, command and control units, long-range radars, and four different types of missiles capable of targeting objects at varying distances and altitudes. The key strength of the S-400 lies in its ability to track and intercept a wide variety of aerial threats, from stealth fighters to ballistic missiles. It is capable of tracking up to 300 targets simultaneously and engaging 36 of them at the same time. Its radar system can detect targets at distances up to 600 kilometres, allowing for early detection and timely engagement.
One of the S-400 system’s most notable features is its speed. The missiles used in the system can travel at speeds of up to 17,000 km/h, which is about 14 times the speed of sound. This allows it to hit even fast-moving targets like ballistic missiles or high-speed drones. The S-400 can operate across a wide range of altitudes, from as low as 10 meters to as high as 30 kilometres, providing coverage for low-flying cruise missiles as well as high-altitude aircraft and projectiles. This makes the system particularly effective in layered defence strategies, where it forms one part of a broader shield designed to counter various threats at different ranges and heights.
India’s decision to purchase the S-400 was not only a military move but also a strategic one in terms of international relations. In October 2018, India signed a deal worth around $5.4 billion with Russia for five S-400 units. This was one of the largest defence acquisitions in Indian history.
Each battery of the S-400 includes multiple missile launchers, radar systems, and command vehicles. The total cost of each complete system is estimated at $1.25 billion, though training, maintenance, and logistics raise the full cost over time. The deployment of the S-400 began soon after the units were delivered, and its inclusion in India’s air defence network has already seen real-world application during recent tensions with Pakistan.
During Operation Sindoor, which followed a major terror attack in Pahalgam, India launched precision strikes on terrorist camps inside Pakistani territory. In response, Pakistan conducted a large-scale retaliation involving drones and missiles directed at multiple Indian cities, including Jammu, Amritsar, Ludhiana, and Bhuj. The S-400 missile system was activated during this operation and was responsible for intercepting and neutralising these incoming threats. Its quick response time and high success rate in the interception process helped avoid considerable damage to civilian and military infrastructure. This marked the first actual combat use of the S-400 by Indian forces and served as a test of its real-time effectiveness, which it passed successfully.
The range of the S-400 system depends on the type of missile used. The 9M96E and 9M96E2 missiles have a range of up to 120 kilometres and are used to tackle medium-range threats. The 48N6E3 missile has a range of around 250 kilometres and is effective against high-speed aircraft and cruise missiles. The most powerful missile in the S-400 arsenal is the 40N6E, which can engage targets at distances up to 400 kilometres. This combination of missiles allows the system to create a layered defensive cover that can target threats from both nearby and distant sources.
In terms of deployment, the S-400 is known for its mobility and quick setup time. All components are mounted on high-mobility wheeled vehicles, which means the system can be moved and redeployed within minutes. It can go from transport to combat-ready in just 5 to 10 minutes. The system’s “shoot and scoot” capability means it can fire its missiles and then quickly relocate to avoid counter-strikes. This is important in modern warfare where fixed locations are vulnerable to enemy detection and targeting.
Another advantage of the S-400 is its ability to work well with other existing systems. It can operate alongside earlier Soviet-era systems such as the S-300 as well as newer ones like the Tor and Pantsir. In India, where the air defence network includes both Russian and Western systems, integration can be challenging. Still, efforts are ongoing to connect the S-400 into this broader network, which includes radar systems and short-range missile systems.
The S-400 has been compared with other modern air defence systems like the American Patriot (MIM-104), China’s HQ-9, and the US-made THAAD. Each of these systems has its own strengths and limitations, but the S-400 stands out for its longer engagement range, ability to handle multiple threats, and mix of missile types. The Patriot system is known for its missile interception accuracy but has a shorter radar detection range. The HQ-9 has some similarities to the S-300 and is less advanced than the S-400. THAAD is built to intercept ballistic missiles at high altitudes but does not offer the same flexibility against other types of aerial threats.
However, the S-400 system also has some limitations. It is a purely defensive weapon and cannot be used to strike enemy targets. In a scenario where India faces threats on both western and eastern borders from Pakistan and China, respectively, the system might face pressure from multiple directions at once. Another concern is that while the S-400 is capable of intercepting a wide range of threats, its effectiveness against newer technologies such as hypersonic glide vehicles has yet to be fully demonstrated. Additionally, the cost of acquiring and operating the S-400 is high, which can affect budgeting for other defence priorities.
Geopolitically, India’s decision to acquire the S-400 has raised concerns in the West, especially from the United States. Under US law, countries buying military equipment from Russia could face sanctions. While India has avoided such penalties so far, future purchases of similar systems could complicate relations with Western partners. This affects India’s efforts to build a diversified defence portfolio that includes both Russian and Western technologies.
Going forward, India must focus on improving training and coordination for S-400 operators. The system includes complex equipment and requires skilled personnel for operations and maintenance. Integration with India’s wider air defence network will also need to be refined to avoid duplication and gaps. A combination of long-range, medium-range, and short-range systems will offer better protection against the full spectrum of aerial threats.
