If we want to effect regime change in Cuba, we need an American embassy in Havana staffed with CIA officers. The only way we can find out definitively what is going on is to have those officers recruit agents inside the Cuban government, as the CIA does in governments all over the world. It's how we can get our tentacles into Cuba.
You’re assuming Obama wants regime change in Cuba, which I highly doubt.
It will be a great place for the Mafia too! Just wait til the legalize gambling!