In 2002, Anatoliy Sokolov, former commander of Russia’s missile and space defense army, confirmed U.S. suspicions that the Gorgon and Gazelle interceptors had become obsolete: “It makes no sense to maintain a dying system, as the existing antimissile defense is unable to provide efficient protection of the area, let alone the entire country.”Originally Posted by M21Sniper
Gorgon/Gazelle was the Soviet equivalent to Spartan/Sprint; Gorgon being exo-atmospheric, Gazelle being endo. Gorgon had a 1 megaton warhead compared to the 5 megaton warhead on Spartan (Spartan was damn big).
In any case, I doubt the Soviet system would have knocked out more than a few incomers, and that is only if the US decided to "go commando" (no countermeasures). The EMP and ionization effects would have rendered the Soviet radars blind to the follow-ons.
The US warheads in those days were extremely EMP-hard. They didn't even use semiconductor memories; they used dinosaur-era magnetic-core memories (which are EMP-insensitive). The newer US warheads use GPS and other sensors for terminal guidance, so they would lose accuracy in a nuclear firestorm over Moscow.