“Fidel mostly sympathised with Potus – in his own way,” said a memo from Jonathan Farrar, the US chief of mission. “Fidel then continued his attempts to walk a thin line between a positive impression of a popular US president and the idea that the evil empire will never change.”

In other Reflections columns, the US nemesis who called George Bush a genocidal drunk praised Obama as intelligent, sincere, serene, honest and well-meaning. He welcomed the president’s Nobel peace prize and called his position on global warming courageous.

Latterly, the commandante’s ardour for Obama began to cool, with a tone of disappointment and sense of betrayal over the president’s stance at the Copenhagen climate change summit.

“Following the conference, Fidel wrote three straight Reflections devoted to attacking President Obama’s participation in Copenhagen. Fidel called President Obama’s conference remarks ‘deceitful, demagogic and ambiguous,'” a cable said.

Cuba’s leader, it noted, had taken to calling Obama the “yanki president”.