He overthrew a brutal right wing dictatorship and established a brutal left wing dictatorship in its place, so from the POV of what's best for the United States, we were better of with Batista.
From the POV of the Cuban people, I don't see that it makes very much difference, although I will admit that I am not too familiar with the details of either regime.
But let's get our facts straight here:
It was not Castro who threatened the U.S. with nuclear weapons.
It was the Soviets. Establishing a Soviet missle base in Cuba was part of the quid pro quo for the economic and military aid that the Russians provided in exchange.
I don't believe that there was ever any doubt that it would be the Soviets who would be in control of the missles and determine if and when they would ever be used.
The whole Cuban Missle Crisis was just another move in the cold war chess game between the Soviet Union and the United States, and Castro and Cuba were nothing more than pawns.
