Big differences with Iraq:

To the best of my knowledge Cuba is not only not now developing any weapons to threaten the U.S., but never had any since the Russian missiles left*. And while Cuba supported communist "liberation" movements across the world during its status as a client state of the U.S.S.R., as far as I know it is too damn broke to do anything like that any more. In addition, unlike Iraq, Cuba does not have a record of trying to conquer neighboring countries.

In other words, while Castro is indeed a goon oppressing his own people, I don't think we can make a plausible case for him being an active threat to the rest of the world.

*There are sources who say otherwise, but not enough of them for my satisfaction. I'm keeping my eyes open though.