During the Cold War, the Soviet Union knew its numerous air forces were no match for the combined Western power. This imbalance partly drove it to invest heavily in air defense. It pioneered air defense systems, rendering the XB-70 Valkyrie obsolete before it could enter service and downing the high-flying U-2 spy plane during the Cuban Missile Crisis. Today, Russia possesses impressive layered air defense systems made up of the long-ranged S-500, S-400 (an upgraded S-300), S-300, and S-200 and the medium-ranged Panstir and Buk air defense systems. This article will focus on the S-400 and S-300 air defense systems.

The Soviet & Russian emphasis on air defense

When the Soviet Union collapsed, Ukraine and Russia had some of the world's most advanced air and missile defense systems. In 2022, they still had two of the world's greatest stockpiles of air defense systems.

"Current Russian air defense doctrine follows a three-tier approach. This layered system allows Russian air defense forces to create anti-access area-denial (A2AD) zones that can be difficult to penetrate. The highest tier of these defensive networks uses long-range systems such as the S-200, S-300, and S-400, providing air defense bubbles potentially up to 800 km in diameter." - CSIS

The old Soviet (and current Russian) strategy (anti-access area denial) appears to have worked for Ukraine. For the year before Western aid defense systems arrived in Ukraine, Ukraine could fend off and deny its airspace to the Russian Air Force. It appears that the Russian Air Force doesn't possess the SEAD (Suppression of Enemy Air Defense) capabilities needed to pick apart the network.

It is difficult to find accurate estimates of how many of each of these systems Russia has in inventory, although it is a lot. While the Patriot is known to have taken down multiple Russian fighter jets and helicopters, it is unclear how many Ukrainian jets have been hit by Russian air defense. Typically, Ukrainian (and Russian) fighter jets avoid airspace defended by long-range air defense systems.

S-300/S-400 air defense systems

The S-300

The bulwark of high-end Russian air defense is the S-300 and its upgraded variant, the S-400. The S-300 is a family of long-range surface-to-air missile systems developed by the Soviet Union (its NATO reporting name is SA-10 Grumple). Today, it is in service in many countries, including a few NATO countries like Bulgaria and Greece (Greece may have withdrawn its S-300s in 2024).

The S-400

The S-400 Triumf (NATO reporting name SA-21 Growler) was previously called the S-300 PMU-3. The S-400 was developed during the 1990s and was approved for service in 2007. The S-400 (and S-300) is the Russian analogue to the US Patriot air defense system. Numerous S-300s and S-400s have been taken out over the last three years (including by US-supplied ATACMS missiles, Anglo-French Storm Shadow/SCALP missiles, and other means).

"The S-400 air defense system is universal for destroying all types of aerodynamic targets and ballistic missiles with a launch range of up to 3,000 - 3,500 km." - Rosoboronexport

It should be noted that there can be a big difference between reported specs and real-life performance. How far an air defense can see is not necessarily how far it can reliably engage a target. While the S-400 may be able to see further than the Patriot, the Patriot can see and engage targets much better when they are within the field of view. In other words, it is extremely difficult to compare the specs of one system with the specs of another without knowing more about how they actually operate.

The S-500

The S-500 Prometheus is designed to supplement the S-400, and the first unit supposedly entered service in 2021 (the S-550 is also planned). There have been conflicting reports on its operational status and whether any units have been hit. The S-500 is intended to be the Russian answer to the US THAAD high-altitude system. While Patriot is designed to be more of a medium-long-range air defense system designed to engage a broad range of targets, THAAD is purpose-built to engage high-altitude targets beyond the reach of Patriot.

Russian/Soviet air defense systems are popular

Today, many countries around the world operate legacy Soviet and Russian air defense systems. Air defense systems were one of Russia's leading military exports before the passage of the United States CAASTA Act (which sanctions countries from purchasing high-end Russian weapons like fighter jets and air defense systems).

Purchasing Russian air defense systems has become a sensitive topic. For example, Turkey was expelled from the F-35 program after purchasing the S-400, while the US allowed an exemption for India to purchase the S-400 (the US isn't selling the F-35 to India anyway). In recent years, Russia's fighter jet exports have collapsed; it's unclear what the status of Russia's S-300/S-400 order book is (India is still awaiting delivery of systems ordered years ago).

Increasing air-defense competition

While the Soviet Union and Russia have been the mainstays of air defense for many countries around the world for many years, the future is unclear. The American CAASTA act makes it difficult for countries to purchase these systems ( Turkey has been trying to find a compromise to be readmitted to the F-35 program ever since the US expelled it).

Additionally, many countries are building or developing their own short, medium, and long-range aid defense competitors (like the Iranian Bavar 373, the Chinese HQ-9 and HQ-22, the South Korean L-SAM, the Turkish Siper, and others). European countries (with NASAMs, SAMP/T, and Iris-T) and Israel (e.g., David's Sling and Arrow family) offer a range of other systems. Some of these air defense systems, like the Norwegian NASAMS and Israeli David's Sling, are also partially United States projects.

Western fighter jets also used in air defense

It should be noted that not all air defense is ground-based. A part of the reason why there are seemingly fewer air defense systems in Western countries is that fighter jets often fill much of the role (against drones and cruise missiles). Ukraine's F-16 Fighting Falcons appear to be used mostly in an air defense role. Recently, Ukraine claimed that an F-16 broke records by downing six cruise missiles in a single mission (four with its four air-to-air missiles and two with guns). Israeli, American, and British fighter jets were also scrambled in 2024 to intercept targets from Iran against Israel.

The S-300 & S-400's mixed performance

For many years, Iran lobbied to purchase Russian S-300PMU-2 systems. Finally, it purchased four systems, and these were delivered by 2016. However, these seem to have been taken out by Israeli F-35s with zero losses (something confirmed by the British). Israel knocked out one radar in a warning strike in April 2024 and the remaining three in October 2024.

For its part, Iran has denied its S-300s were taken out. Iran also claims its domestically produced Bavar-373 long-range surface-to-air missile system is superior to the Russian S-300 system. The Bavar-373 was first unveiled in August 2016 and formally unveiled in 2019, and Iran has said it has no interest in purchasing new S-400s from Russia. Iran claims an upgraded variant of the Bavar-373 is a competitor to the S-400.

On 16 May 2023, Ukrainian Patriots fended off a mass strike (that included six 'hypersonic' Kh-47M2 Kinzhal missiles). US Army air defender and Patriot operator Sgt. Ethan Long noted that the strike was well within what the Patriot could handle. However, he stressed that the strike package revealed more about the capabilities of Russian systems. He said Russian planners likely thought the strike package would be enough to overcome the Patriot as it would have overwhelmed a Russian S-300 or S-400.

World's largest ground-based air defense system

Russia may maintain the world's largest ground-based air defense system (at least if the Aegis-equipped US Navy is excluded). The S-300s and S-400s remain formidable air defense systems and are in demand worldwide. However, they have proven vulnerable to a variety of threats in Ukraine. Additionally, recent developments in the Middle East raise questions about how effective Russia's aid defense systems are against cutting-edge platforms like the fifth-generation F-35 Lightning II fighter jet.