What Walter Kendall Myers kept hidden, according to documents unsealed in court Friday, was a deep and long-standing anger toward his country, an anger that allegedly made him willing to spy for Cuba for three decades.

“I have become so bitter these past few months. Watching the evening news is a radicalizing experience,” he wrote in his diary in 1978, referring to what he described as greedy U.S. oil companies, inadequate health care and “the utter complacency of the oppressed” in America. On a trip to Cuba, federal law enforcement officials said in legal filings, Myers found a new inspiration: the communist revolution.