Historyman?
Bzzzzzzzt.
Soviet Reliability: LOW.
Soviet nuclear practice: Hilariously very much "Eeeeh..." Soviet C3 at this point is not good enough to respond short of a hour, given that Soviet practice was to actually not keep weapons mated.
Given reliability, reaction, et al, and that they had kept the WP at low positioning? It's quite possible NATO gets their deployed warheads first, and hammeres them other ways, as well. As for their ICBM: Let's be kind: 18 are ready to launch, all single warhead: Vs a clutch of nuclear tipped NIKE-HERCLUES. Nuff said.
In the thought the Sovs (the K-19 firing a nuclear torpedo, all things considered is the most likely) trigger an strike, via the method suggested, I'd say this: Germany, Turkey, Alaska, Guam, maybe Hawaii and Korea get hit, and to some degree of 'hard' with nukes, or heavy conventional forces. Japan, France, Greece less, Norway iffy, Britain Iffy. ZI? Using some off the back, figure the Russians luck out and get 12 missiles off (assuming reliability rate of 66%, 50% alert). Vs. the Nike-Herc systems? I'd not put money on those getting through. Just because "If it works, we're heros."
Bombers? Excuse me while I laugh.
Unless the forces on the island are cocked, locked, and fueled, not a chance.