I was garbling a scenario from Ellsberg's book. I believe the time period in question was the 50s-early 60s (the same period where these tactical nukes were popular) when MAD was being enforced by bombers, not ICBMs.

According to Ellsberg, there was a period where there was no actual plan to defend Europe by other means than massive nuclear retaliation.

https://www.amazon.com/Doomsday-Machine-Confessions-Nuclear-...