Pardon me, but is it the U.S. that officially calls Cuban political dissenters "gusanos" (worms)? Is it the U.S. that imprisons Cuban political dissenters for their opposition to the government? Is it the U.S. that won't let Cubans leave Cuba? Is it the U.S. that doesn't allow free elections in Cuba? Is it the U.S. that doesn't allow free press in Cuba?
If Cuba's economy is so delicate that people live in squalor and misery without U.S. trade (and they don't - Castro says they have wonderful lives in his socialist workers' paradise, and he wouldn't lie about something like that), why doesn't Castro either 1) institute the necessary social reforms so that the U.S. would lift the embargo, or 2) take the necessary steps to invigorate his economy without U.S. support - i.e., ditch communism?