This was a serious proposal, probably made by a sociopath like Gen. LeMay, to execute a specific attack in 1963, before Soviet capability caught up.
Per LeMay:
> Native annalists may look sadly back from the future on that period when we had the atomic bomb and the Russians didn't. Or when the Russians had aquired (through connivance and treachery of Westerns with warped minds) the atomic bomb - and yet still didn't have any stockpile of the weapons. That was the era when we might have destroyed Russia completely and not even skinned our elbows doing it.