Not sure what decade you are living in, but the USSR ceased to exist almost twenty years ago. And Cuba.... Well, who knows if Castro is still alive and his brother Raul is not even half as bad as Fidel was in his youth. So the US has no reason to send an airstrike to Cuba. Didn't happen during the Cuban Missile crisis, nor the cold war. It ain't gonna happen now!
The Berlin Airlift proved to the USSR the US would not let Berlin be cut off. The USSR wanted to starve Berlin into joining them.
The USSR.
Eisenhower prevented Patton's 3rd army to advance on Berlin. Patton's tanks and troops were making unprecedented progress towards Germany. Patton urged Ike to allow him to advance to no avail. The terrible results were that the USSR did capture Berlin. If Patton succeeded then things like the Berlin Wall and the Berlin airlift crisis never would have happened.
Allies had to air lift supplies into West Berlin because the USSR had all roads blockaded. The eastern part of the city was under the control of the USSR, and the western region was under the control of the allies. The USSR hoped that by shutting off all routes, the allies would turn total control of Berlin over to them.
Who would control the German capital of Berlin .
USSR
After WWII, Germany was defeated by the allies and divided. East Germany was run by the USSR (Russians). Berlin, the capital, was located in East Germany, but was controlled by the USSR and the western allies. The Berlin wall was build to keep the East Germans in Eastern Berlin from entering Western Berlin of Western Germany.
After the falling of the Berlin wall and the ending of the USSR, Bulgarian is no more communistic country.
It is likely that if nuclear weapons did not exist, the US and the USSR would have gone to war in the 1950's, and the question of the divided city of Berlin would have been resolved by war, rather than building a wall.
The USSR in may 1945
USA, UK, USSR and France
The airlift