Even during the Cuban Missile Crisis they had a serious lack of survivable long range delivery systems. Looking at the nuclear ORBAT at the time, the Russians would be lucky to get a dozen nukes delivered to CONUS compared to the thousands the US would have been able to deliver.
He was consistent. His advice always was to nuke the soviets, going all the way back to 49.
I think he was right. 1963 was pretty much our last chance to destroy the Soviet Union before they reached parity with us.
Oh, and it was Kennedy blundering the Cuban invasion that actually caused the Cuban missile crises. Castro demanded the Soviets put missiles onto the island to deter further American aggression against him.
Kennedy really bungled that.
"Mr. President, I'm not saying we wouldn't get our hair mussed. But I do say no more than ten to twenty million killed, tops. Uh, depending on the breaks."