Cuba would have been invaded by the US, it is literally right next door, we could not let them be communist
I'm not quite sure the Soviet Union or the world community in general would be happy about that. I think everyone is vastly overestimating the capabilities of the United States. The United States was able to get away with the operation because 1.) it was covert and 2.) it was a success. Should the Bay of Pigs fail, both the Cuban and Soviet leadership are going to use it as a rallying cry. Cuba is going to have Russian backing for a long time. Castro is likely to be replaced with someone else though.
In addition, if the Bay of Pigs failed it would probably tarnish Kennedy and Eisenhower's reputations. It wouldn't ruin them, but it would create problems.