Nowhere in the Western Hemisphere. The U.S. would fight to win in the Americas and would be backed by a solid majority of the population. ....
So...why
haven't we invaded Cuba already, any time in the past 50 years?
During much of that time it was pretty well established that Cuba was under the Soviet nuclear umbrella, to be sure. Part of the settlement of the Missile Crisis was a promise from us that we would not invade.
Another outcome--not so well known to the USA to be sure--was that given Castro's gung-ho willingness to risk triggering WWIII
during the crisis, the Soviets yanked out not only the big missiles the Americans were watching, but the small tactical weapons another poster mentioned. Those had been directly in Cuban hands, true--but Khrushchev was not going to leave them there! The Russians took them back and out of the hemisphere.
Whether or not they might have guessed Americans knew about them, the fact is, we didn't. We know about these things now because of a historical conference between Americans and Russians in the 1990s. The Soviets took them back because they didn't want the Cubans to get trigger-happy with them and they felt Castro had just demonstrated that he might.
So actually I am not 100 percent sure the Soviets would have necessarily escalated to nuclear weapons to defend Cuba. But there was a chance they would and that was enough to deter us.
But before the Crisis, we
did try to intervene of course--that was the Bay of Pigs.
If what you say is so open and shut, CalBear, you need to explain why even then the intervention was so indirect and limited, and why we did not immediately escalate to a more direct and massive one when that failed.
I think the answer is, that cooler heads realized that Cuba could indeed become a quagmire, no matter what level of resolve the American citizen had to see it through. That's without the Soviet nuclear coverage to consider.
Vietnam of course was just as much in the Soviet sphere as Cuba was.
Again--once the USSR collapsed, the question comes up, why has the USA not invaded Cuba since 1991? Again I think the danger is that it would become a quagmire.
There is no question in my mind that with sufficient firepower, one can suppress any movement. And that the USA had that firepower. The thing is, such firepower accomplishes the suppression by means of genocide (and certainly in the case of Vietnam, ecocide as well). Enough firepower to "win" in Vietnam would have been tantamount to nuking the place. I think the same would be true in Cuba. The Cubans, isolated from Soviet supplies, would not have been able to inflict as much damage on the Americans--but it still would have been necessary to kill huge numbers of Cubans to "save" them from Castro. And then stay in a very hostile country for decades to try to get them to vote the way we wanted them to. And probably fail. We might wind up killing them all, but we'd never get a nice friendly pro-American regime--not one that didn't depend on a police state that makes Castro look like Santa Claus by comparison anyway.
(A police state that could not possibly fund itself--they'd be utterly dependent on very expensive US generosity, for as long as we cared to prop them up, and utterly unable to stay in power the minute we didn't. Or sooner...)
One can blame "hippies" all one wants. The point is, inevitably a genocidal quagmire for questionable reasons fosters dissent. The hippies were hardly some alien infection--they were perfectly normal Americans, who reacted to a bad situation in a way I think was downright admirably patriotic--in terms of the stated values of the United States.
So yeah. If it is as ASB as some people think here for the USA to have had a Communist revolution, it's partially because our ruling class is not as bloody stupid as some people would like them to be. If they did something as bloody stupid as invade Cuba...well, that would be my POD for a Communist USA, by 1975 or so.