Fidel Castro begrudgingly admitted that Cuba was so desperate financially in the 1980s that he turned to a banker from the one country he hated the most: the United States.

"It was the year of the Marielitos"—the 1980 Cuban boatlift— "and he was under a lot of strain to be able to service the debt to the European banks who had lent to him, and also to some Canadian banks," Bill Rhodes, a former Citigroup executive and author of "Banker of the World," said. For decades, Rhodes was Citigroup's Latin America liaison for decades.

Castro requested a meeting with Rhodes for financial advise. The prime minister told Rhodes he regretted kicking the International Monetary Fund out of Cuba in his early days of the communist revolution.

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