The assumptions that the USSR collapses as OTL, and that Soviet "advances" stop with West Berlin are very likely overly optimistic. Once US nukes are unmasked as only for use in retaliation for a nuclear attack on the US itself (which is what this scenario implies) then the US and Western Europe have to try and match the USSR conventionally beginning in the early 1960s. This means a huge expenditure on these forces, money which is diverted from more useful investments. The result of this is that the US and "western" (I include Japan and Korea here) economies do not grow as much as they did OTL, and probably a measurable amount of the tech advantage the west built up over the Soviets between the 1960s and 1989 does not happen as the consumer market that drove a lot of this is reduced.
One of the big Soviet diplomatic talking points for years was a "neutral" Germany - Soviet forces withdrawn from East Germany NATO from the west. In the wake of an unopposed takeover of Berlin, the West Germans may very well decide that NATO/USA won't fight for Bonn either so the best shot at independence and preventing Soviet forces from trashing West Germany is this neutralization scheme. The French, in this case, very likely go their own way with their "Force de Frappe". The Dutch, Belgians, and Danes if they stay in NATO have small military forces no matter what, and literally very little place to put US forces. Norway decides to work with Sweden and Finland to create a Scandanavian Pact of armed neutrality. At a minimum, European countries are more willing to trade with the USSR absent some of the technology transfer restriction NATO agreed to.
Since the USSR is seen as more muscular or more a winner than the USA, will this embolden the Russians to work with Cuba in Central/South America? Why not, the reality was a lot of US supported governments treated the bulk of their population like crap the Cuban/Soviet model was attractive. Not to see the reality was necessarily better but...
Perception may not be everything, but it means a lot. In the early 1960s the Soviet system/economy was not seen as the creaking mess it was/became. ITTL the USSR is seen on the march forward, the USA in the other direction. I am not saying that throwing nukes around is a good thing, it is not. The reality is, and this has shown true throughout history, that if you start making threats you don't follow through on, the other side pretty soon discounts them. This in turn leads to further "negative" acts by the other side because they anticipate no reaction and eventually a true red line is crossed and bad things happen all the way around.
The USA, NATO, and the "west" in general made the conscious decision that the way to go was to build a nuclear club to deter Soviet aggression rather than build a conventional force that would serve the same purpose. Cost to the western economies was a prime reason, once you have the factories nukes are cheaper than armies, tanks, etc. The USA chose to spread the "nuclear umbrella" over NATO (and ANZUS, and Japan, and Korea) in part to be able to say to most of those countries "you need not build nukes, we got that covered for you". Let the Soviets get away with conventional aggression, without resisting because it might lead to using nukes, and this whole system goes down the tubes. Yes it prevents nukes today, which is a good thing, but what happens next week.
The reality was the USSR operated under a governing philosophy that communism was inevitably going to rule the world, that the USSR was "in charge" of this change and was going to be the center of it. They played (or tried to) play a long game, never pushing so hard that the west would push back militarily in a big way.There was always going to be a next bite - this was not some dynastic spat over a province or two.