article_snippet: of the Republic for spying on anti-Castro extremist groups in .
article_snippet: by U.S. intelligence services,' Castro wrote.
article_snippet: home on December 17, when Cuba and the United States completed a . prisoner swap as part of the deal in which Cuba and the United States agreed to .
article_snippet: spying on anti-Castro extremist groups in the United States were arrested in 1998 and convicted in 2001 for spying for Cuba's government .
article_snippet: In exchange, Cuba freed a Cuban man who spied for Washington . and spent nearly 20 years in jail.
article_snippet: In addition, Cuba freed .
highlights_snippet: Castro insist they did no damage top the U.S. and were 'trying to impede terrorism' oversees .