(Newsmax) Former CIA operative Bob Baer’s newest book on assassinations hasn’t even been released yet, and he told MSNBC’s “Morning Joe” federal officials have already told him there’s a threat on his life.

Baer’s book, “The Perfect Kill: 21 Laws for Assassins,” due out Tuesday, details the history of political murder. Last month he said the FBI contacted him with advice to restrict his travel out of the country.

“A month ago I got a call from the FBI. [They] said, ‘We have a credible threat on your life.’ The CIA showed up in Los Angeles . . . said … ‘Don’t go overseas.’ I said, ‘For how long?’ [They said,] ‘We don’t know,'” Baer said Monday.

Baer speculated the reason stemmed from an advance copy of the manuscript he sent to a journalist in Lebanon for “fact checking.” He explained that in the book he “took a whack at the Iranians,” and made accusations that included a claim they killed the president of Lebanon in 1989, Rene Moawad.

He said he also “worked with a special tribunal in Lebanon” on the assassination in 2005 of Lebanese Prime Minister Rafic Hariri. Baer said while those matters made little difference to many people, it “really hit home” for the Iranians.

Baer compared assassinating someone to cancer, and explained a target was identified as “somebody whose removal, like a cancerous cell, will make things better for everybody.”

The problem with targeting leaders of the Islamic State (ISIS) with assassination was that the militants would continue fighting, because “it’s an idea, not a man,” Baer said.

Similarly, with Syrian President Bashar al-Assad, he said the leadership that would follow him was uncertain, because “we really don’t know if we assassinated him today what we’d get.”

“There’s 80 generals standing behind him, and somebody may be worse than he is,” he said. “Nobody knows for sure how that leadership works, so it would be a shot in the dark.”

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