During the Cold War, the Soviet Union invested heavily in its air defense systems. As a result, Russia now possesses some of the most advanced air and missile defense systems in the world. Russian air defense systems are also highly proliferated and are currently in use by dozens of nations around the world. Furthermore, many countries have developed variants and begun indigenous production of these weapons 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.
These zones are typically augmented by the second tier which includes medium-range systems like the 9K37 Buk and its variants. This medium-range layer is intended to increase radar coverage within the air defense zone and augment the more limited inventories of longer-range interceptor missiles. The third tier uses mobile short-range systems like the 9K33 Osa and S-125 Neva to provide extra protection for key areas such as military bases. These systems, along with highly mobile systems like the 9K37 Buk are often also attached to formations of ground forces in the field.