International Relations★ Must Know

Fourth S-400 Sudarshan air defence squadron arrives in India from Russia

By TestNeeti Editorial TeamPublished Monday, 6 July 2026 2 min readSource: CA - India-RussiaArticle 11 of 26

The fourth squadron of the S-400 Sudarshan long-range air defence systems has arrived in India from Russia, defence sources confirmed, significantly enhancing the country's air defence capabilities. The system reached India by ship and will be deployed in operational areas shortly. The delivery is part of a 2018 contract under which India agreed to procure five S-400 squadrons from Russia; three squadrons arrived two years ago, while the remaining two were delayed due to the ongoing Russia-Ukraine conflict. The S-400 played a critical role in Operation Sindoor, achieving the longest recorded surface-to-air kill by downing a high-value Pakistan Air Force surveillance aircraft flying at over 300 km. The fifth squadron is expected within months, and the Defence Acquisition Council (DAC) has approved acquiring five additional squadrons.

Key Facts & Details

8 points

1
The fourth squadron of the S-400 Sudarshan long-range air defence system arrived in India from Russia by ship and will be deployed in operational areas shortly.
2
The delivery is part of a 2018 contract under which India agreed to procure five S-400 squadrons from Russia.
3
Three squadrons arrived two years ago, while the remaining two were delayed due to the Russia-Ukraine conflict.
4
The S-400 played a critical role in Operation Sindoor, achieving the longest recorded surface-to-air kill by downing a Pakistan Air Force surveillance aircraft flying at over 300 km.
5
The fifth squadron is anticipated within the next few months, and the Defence Acquisition Council (DAC) has already approved acquiring five additional S-400 squadrons.

Deep Dive

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India is simultaneously advancing an indigenous air defence programme codenamed Project Kusha, aimed at neutralising enemy drones at ranges comparable to the Russian S-400.
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Indian defence firm Solar Industries is participating as a development and production partner in Project Kusha.
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The arrival strengthens India's layered air defence network at a time when the DAC has cleared further S-400 acquisitions.

Exam Focus

Which country supplies the S-400 Sudarshan, and how many squadrons did India contract for under the 2018 deal?

Exam Relevance & Angle

Defence acquisitions like the S-400 Sudarshan are high-frequency current-affairs topics for banking, SSC, railway and UPSC exams, where examiners test the supplier country, the number of squadrons, the contract year and the system's operational role together.

Target Exams

SBI POIBPS PORBI Grade BSSC CGLUPSC CSEState PCS

Background & Context

The S-400 is a Russian-built long-range surface-to-air missile system designed to intercept aircraft, drones, cruise missiles and ballistic missiles at extended ranges. India signed a landmark government-to-government deal with Russia in 2018 to acquire multiple squadrons, making air defence a central pillar of its modernisation drive. The Defence Acquisition Council (DAC), chaired by the Defence Minister, is the apex body that approves capital procurement proposals for the armed forces. India also pursues indigenous alternatives to reduce import dependence, in line with the self-reliance push in defence manufacturing.