S-400 Air Defence System: Strategic Deterrent for India

Why in News?

India is set to receive the remaining two units of the S-400 air defence system from Russia by 2026. Additionally, the Indian Defence Ministry’s Defence Procurement Council has approved the purchase of five more Russian S-400 long-range air defence systems. 

What is the S-400 Air Defence System?

• S-400 Triumf is considered one of the world’s most advanced air defence systems that can simultaneously track and neutralise a range of incoming objects over very long ranges.
• Developed by Russia. S-400 is a successor to the S-300 system. 
• The surface-to-air missile system can provide air interception against:
  • fighter aircraft, stealth aircraft, AWACS aircraft 
  • airborne missile strategic carriers
  • unmanned aerial vehicles 
  • ballistic missiles and cruise missiles
• The S-400 is fully mobile. Capable of firing four types of missiles to create a layered defence net for up to 40 km, 120 km, 250 km and a maximum range of 400 km.
• Altitude: It can destroy targets at a height of 10 metres to 30 Kilometres. The different ranges and varying altitudes create a layered air defence net. 
• Each system has a 3D phased array acquisition radar that can track around 300 targets, a command and control centre, automatic tracking and targeting systems, launchers and support vehicles. 

India signed a $5.43 billion deal with Russia in 2018 for five squadrons of the S-400 system. Russia has delivered three units- deployed in Pathankot (Punjab), Rajasthan, and Gujarat. The remaining units will be delivered to India by 2026. Despite the fear of sanctions from the US under the Countering America’s Adversaries Through Sanctions Act (CAATSA), India and Russia signed a contract. 

Why is the S-400 important for India? 

S-400 has been named ‘Sudarshan Chakra’, inspired by the mythological weapon of Lord Krishna.

• Proven layered air defence system: The S-400 system has already demonstrated its operational effectiveness. During Operation Sindoor (2025), the deployed systems played a critical role in intercepting and neutralising incoming missiles and drones, significantly bolstering India’s air defence capabilities. 
• Complements India’s indigenous Ballistic Missile Defence system developed by the Defence Research and Development Organisation (DRDO).
• Fills gaps in the Indian Air Force (IAF): The S-400 would make up for its falling fighter aircraft squadrons in the medium term. 
• Strong deterrence: Given its long range, the system can track the movements of Pakistan Air Force aircraft. Enhances India’s strategic deterrence against China. 

The S-400 can be seamlessly integrated into the country’s existing air defence network, thereby strengthening national security against evolving aerial threats. 

Practice MCQ:

Q. Consider the following statements regarding the S-400 air defence system:

1. It is a long-range surface-to-air missile system developed by Russia.

2. It can engage aircraft, cruise missiles and ballistic missiles.

3. It is a submarine-launched missile system.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 only

(c) 1 and 3 only 

(d) 2 and 3 only 

Answer: (a)

UPSC Mains PYQ (2021)

Q. How is the S-400 air defence system technically superior to any other system presently available in the world? 

UPSC PYQ 2014

Q. Which reference to Agni-IV Missile, which of the following statements is/are correct? 

(1) It is a surface-to-surface missile.

(2) It is fuelled by liquid propellant only.

(3) It can deliver one-tonne nuclear warheads about 7500 km away.

Select the correct answer using the code given below.

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (a)