If a war starts off nuclear, with pre-planning that is one thing. That means the Soviets spend a lot of effort in locating the CVBGs as best they can and if possible putting either a surface or sub trailer on them, and send out the strikes with nukes as the first attack. Part of the problem is timing - nuke a CVBG even 15 minutes before a general attack at in that extra 15 minutes of warning other US/NATO assets go to first alert, even more bombers get off the ground etc. Do the big launch too much before the carriers are hit and again the CVBG is at max readiness AND expecting a nuclear attack. With "Able Archer" if the USSR had responded to what they thought was an attack, the carriers would be pretty home free. Unless there was a Soviet sub with a nuclear torpedo or missile close enough who got "the word" before the USN hit them, airstrikes won't be out looking for them any time soon. First they have to find the CVBG, also getting nuke warheads on the ASMs is going to be time consuming - and this assumes those airbases won't be vaporized before those aircraft are armed and flying.