After the actions in Afghanistan, Iraq, and now Lebanon it seems to be clearly evident that at the end of the end of the day, military action may end a regime but it doesn't change attitudes. One could dethrone the Taliban, Saddam, and kill Hezbollah senior leadership, but if the local public still agree with what they stood for, the fighting will not end.
Change has to come from inward if local attitudes are to change. Imposing a new political system doesn't seem to work. What about this approach: Long term sanctions and patience are the key to fighting corrupt regimes.
Fidel Castro won't live much longer, and his "revolution" could very well end with his death. Even the most ardent supporters of his regime support Castro more so than his political system. Would they trust a one man government if that one man at the top wasn't Castro? I doubt it. Of course I don't even have to mention how the pro-democratic parties in the country feel about having a democracy.
Patience, however, is not a strong point when it comes to American foreign policy. Generally speaking, Presidents want and need results, for reasons ranging from politics to legacy. It would take real leadership for a President to say in his 8 years in office, he plans to do nothing about Cuba. For his time in office, he's just going to keep the status quo and wait them out. For his policy to work, the man/woman who follows him would be expected to do the impossible: the same thing.
If after Castro dies and Cuba begins a democratic process, then we might be able to start looking at Cuba as a case study.