American Ana Belen Montes – one of the most notorious Cold War spies caught by the US – was released from prison on Sunday, two decades after she was convicted of spying for Fidel Castro’s Cuba.

She was working at the Department of Justice when she caught the attention of Cuban agents, and then landed a position as an intelligence expert at the Military Intelligence Agency (DIA).

The now 65-year-old military intelligence analyst was accused, among other things, of passing on to Havana the names of US agents working in Cuba and details of US naval maneuvers.

Arrested on September 21, 2001 by the Federal Bureau of Investigation (FBI) at Bolling Air Force Base south of Washington, D.C., Montes admitted to spying for Cuba for nearly a decade, from 1992 to 2001, although the FBI suspects that she began spying. since 1985.

U.S. officials say Ana Montes is one of the “most dangerous spies” caught by the United States. “It compromised everything — practically everything — that we knew about Cuba and how we operated in Cuba,” said Michelle Van Cleve, who served as head of counterintelligence under President George W. Bush.

She was sentenced to 25 years in prison and the judge said she had endangered “the nation as a whole”.

However, unlike other high-ranking spies caught during the Cold War, Montes was driven by ideology rather than personal gain. She agreed to work for Cuban intelligence, in part because of her opposition to the Reagan administration’s activities in Latin America.

The Defense Department report said it was angered by US support for Nicaragua’s Contras, a right-wing rebel group suspected of war crimes and other atrocities in the country.

She was initially approached by a colleague at Johns Hopkins University in 1984 after she expressed outrage at US actions in Nicaragua. She was later introduced to a Cuban intelligence agent, and during a dinner in New York, she “agreed without hesitation to work through the Cubans to ‘help’ Nicaragua,” the report said.

Montes, who was born on an American base in Nuremberg, Germany, used short-wave transmitters and a public telephone located near the Washington Zoo to transmit encrypted information using a program provided by Cuba.

Ana Belen Montes was convicted by a colleague in 1996, but US authorities did not open an investigation against her until four years later (AFP, BCC)