The religions that romans had the most difficulties with were
faiths that had more than one supreme being
egyptian, syrian, and other eastern religions whose gods were shaped like animals or half-animals
monotheistic religions that prohibited followers from worshipping the gods of the roman state
the greek philosophies of plato and aristotle.

so, based on the research i've done. the u.s. government were always on a wild goose chase just to take down castro. he then retired his trone to his brother raul in 2008 due to some health issues. so it's obvious your answer would be:

castro had no allies from which he could receive aid.

hope this and have a fantastic day!

                                                    -wolfiewolffromsketch