“Cultural exchanges with foreign countries are the most effective propaganda” (Soviet KGB, May, 20, 1981)
Russian intransigent (and Armando Valladares' Human Rights Foundation colleague) Vladimir Bukovsky has a website dedicated to exposing smuggled Soviet documents. The highlights of some of these secret documents have been translated into English. I call your attention to the last item on this link:
Update: (Our friend Ray alerts us to a month-long Castro propaganda (cultural exchange) blitz just kicking off in New York) titled Cuba Si!