Fortunately, having plans in place and actually carrying out these plans are two completely different things.
One UK political leader has had the courage to admit that even if the UK had received a nuclear attack from the Soviets he would not have launched a retaliatory strike. After all, if your deterrent fails - what exactly is the point in using it? [Not something you can admit at the time, of course.]
Would a West German political leader really have agreed to nuclear land mines being used? Most of the weaponry in the Cold War was there for posturing - no political leader ever expected to use them. Even Khrushchev (who was clearly a hard bastard) could only cope with the thought of nuclear weapons by accepting the fact that they would never actually be used - it was all a bluff.
They certainly did contemplate that as valid military options - they had even placed nuclear "mines" (underground room-sized nukes) in [less] populated friendly areas, planning to detonate them below enemy divisions if/when they are forced to retreat. So even nuking your own civilians was considered as an acceptable cost in case of a hot war.