Is Pope Francis a Communist?

On his way back from the Victory Day Parade in Moscow last month, the Cuban leader Raul Castro stopped off in Rome to thank Pope Francis for his role in Cuba's rapprochement with the United States. "If the Pope continues this way," Castro said afterwards, "I will go back to praying and go back to the church - I am not joking."

In September Francis will return the compliment with a stop-over in Cuba when he travels to the United States. And the American visit could turn out to be the most difficult overseas trip of his pontificate.