Anti-Ballistic Missile (ABM) network
Russia’s current primary ABM system is equipped with 68 silo-launched Gazelle (53T6) missiles located at 5 sites around Moscow.
The Gazelle is the only operational ABM system in the world generally considered capable of shooting down inter-continental ballistic missiles (ICBMs). Although there have been similar systems developed by both USA and USSR in the past, the Gazelle is the only system remaining. The proliferation of ABM systems in recent years has focused on intercepting short range and medium range missiles – ICBMs are an order of magnitude faster than even MRBMs and more commonly employ multiple re-entry vehicles.
When considered against the number of ICBMs in American service the 68 missiles seems inadequate to offer complete defence, but rather defence against a ‘rogue’ launch. The number of ABMs deployed was actually limited in the 1972 ABM treaty, but the US’s retraction from the treaty has not been met by Russia deploying more Gazelle sites – instead Russia retired the complementary 51T6 Gorgon system (together with Gazelle these formed the A-135 ABM system) and replaced the Gazelle’s original 1Megaton nuclear warhead with a conventional one. The now redundant Gorgon sites, which have silos compatible with the Gazelle missile, do not appear to have been reused to deploy Gazelle.
Key to border deployment. Note that these are my groupings and do not reflect the Soviet organization of these assets:
A. Kola peninsula and Severodvinsk area. Major naval bases including ballistic missile submarine bases.
b. Baltic coast. Baltic states now independent.
c. Belarus and Ukrainian border with Warsaw Pact.
d. Ukrainian coast. Covering NATO ingress routes from Greece and Turkey.
e. Crimea. Major naval and aviation bases. Strategic location.
F. Eastern Black Sea coast. Covering NATO ingress routes from and Turkey.
G. Caucasus states. Covering NATO ingress routes from Turkey, and US Ally (until 1978) Iran.
H. The Great wall of USSR.
The arctic north was generally not covered by SA-2 sites. The border with Finland also appears to be sparsely covered
Moskova
Today Russian Air Force SAMs are positioned to defend strategic targets and major cities, and not in the ‘great ring’ of Soviet times. Although there are some 64 SA-10/SA-21 sites, plus one or two SA-5 and possibly some SA-2 sites, this is nowhere near the quantity of SA-2, SA-3 and SA-5 sites simultaneously deployed during the height of the cold war. There is clear open source imagery evidence of substantial open storage of SA-10 vehicles and components in several locations and serge deployment could see many more batteries deployed, but still nowhere near enough to cover every inch of territory. The 400km SA-21 system will greatly increase the footprint but it seems unlikely these will be deployed much different to the current SA-10s
In part this is a factor of the sheer size of Russia – even the smallest circles in the above image are 200km in radius! The radar coverage varies greatly depending on target altitude and radar cross-section.
The massive ‘black hole’ in Siberia is also target-less, it can be argued with some credence, that defending the Siberian wastelands is pointless as there is nothing to defend. At any rate only the USAF has aircraft which could conceivably take advantage of the black hole.