In retrospect, the danger certainly was exaggerated. Even though Cuba is very near to the United States, it does not now seem plausible that a communist Cuba could ever have been a major threat to the US. Its importance also is decreased by the fact that technology soon made geographical proximity much less important. In other words, the USSR was soon able (soon after the Cuban Revolution) to destroy the US just as completely using ICBMs launched from the Soviet Union, and later even from submarines, as it ever could have from Cuba.
Cuba was never going to be a base for an invasion of the US. It was not relevant for long as a base for nuclear missiles. Its revolution did not spread to all the rest of Latin America. Therefore the revolution was not as dangerous as was thought at the time.