2K11

The 2K11 Krug, known to NATO as SA-4 Ganef, was one of the Soviet Union's major mobile army air-defence systems. It was designed for a different problem than point-defence weapons: field formations needed a tracked missile system able to move with operational forces and engage aircraft at medium to high altitude. GlobalSecurity identifies the SA-4 within the Soviet/Russian missile inventory, while specialist profiles emphasize its role as a mobile long-range layer in ground-force air defence.

Krug was a system rather than a single vehicle. Its batteries used tracked launchers carrying large missiles, supported by acquisition and fire-control radars. The tracked chassis allowed the system to accompany armored and mechanized forces better than fixed or truck-only systems. The missile's size gave useful reach but also made the launcher and support train large. This balance made Krug a serious area-defence asset for its era, though later systems improved reaction time, electronics, and resistance to countermeasures.

In service, 2K11 Krug batteries offered protection against aircraft operating above the reach of short-range systems. The system's mobility made it well suited to defending army-level assets, routes, and maneuver forces, but its radar emissions, large vehicles, and aging electronics became liabilities as air warfare evolved. Many operators eventually replaced or supplemented Krug with Buk, S-300V, or other modern systems. Even so, its design shows how seriously Soviet doctrine treated layered protection of land forces from air attack.