We trade with China and give them very favorable terms. In fact, we can't send our money over there fast enough. But what terrible things has Cuba done that China hasn't? Plenty of human rights violations and political oppression in both places...in terms of sheer numbers of political imprisonment and executions, I don't think Cuba even comes close. I guess the only difference is that China isn't presently led by a guy who permitted U.S.-aimed missles to be installed in his country. For this reason, I guess I am hopeful that trade will open up with Cuba once Castr kicks it...that would put Cuba in the same boat as China at that point. Of course, looking for internal consistency in foreign policy isn't always a safe bet.
I think opening up trade-especially tourist trade-with Cuba is a great way to undermine Communism. My folks went to Vietnam a few years back, and tourism was undercutting Communism all over the place. If a tourist comes into your country, he's going to get around, buy stuff, eat at private restaurants, visit farms (wink), and so on. Money changes hands and Big Brother doesn't get his cut.