Many people believe, as Ralph Peters does, that President Trump was a "gift to Fox," and "Fox in turn is a gift to Trump."

The difference is that Peters worked at Fox News for years.

Peters, a retired US Army lieutenant colonel, was a Fox military analyst until March, when he resigned and burned the proverbial bridge. In a letter to his colleagues, he accused Fox of "assaulting our constitutional order and the rule of law."

Peters' statements shocked the TV news industry at the time.

On CNN's "Reliable Sources" on Sunday, he had more to say. "People that only listen to Fox have an utterly skewed view of reality," he said. He described the relationship between the president and his favored news network as a "closed loop," but that was hardly Peters' most strident critique of his former employer.

"Fox isn't immoral, it's amoral," he said. Later in the interview, when Reliable Sources aired clips that show Fox News hosts defending Trump's decision to strip former CIA director John Brennan's security clearance, Peters was asked if he thought his colleagues at Fox are "proud of their performance."

"The polite word is 'prostitutes,' so I'll just leave it at that," Peters fired back.

Peters garnered attention on Sunday for his stunning denunciation of Trump.

"Trump gives us something new to worry about virtually every day, but it's important not to lose sight of the overall picture," Peters said. "This is a distinctly un-American president who really doesn't seem to like America very much, certainly doesn't respect it. And he's a president who appears to be enthralled to a foreign power, a hostile foreign power."

That foreign power is Russia. Peters, who was a Russia analyst earlier in his career, has previously said he believes that Vladimir Putin "has a grip on President Trump."

On "Reliable Sources," he said he was speaking out because he believes Trump and his aides are a "real threat to our republic."

"What we need is people who will speak honestly and say what they believe and not worry about who it offends," Peters said. "I'm just sick and tired of people hedging and hemming and hawing. This is a president of the United States who is a danger to the republic."

Peters was harshly critical of former President Barack Obama during his tenure at Fox.

He once called Obama a "total p***y" on the air -- and was suspended for two weeks.

But his criticism of Trump is different. He said on Sunday that Trump "does not respect our system of government," does not understand it, and does not respect the Constitution.

Peters resigned from Fox back in March. He wrote in a note to a handful of colleagues at the time saying he "long was proud" of his association with Fox, but now he's "ashamed," calling it a "propaganda machine" for the president.

A Fox News spokeswoman said Sunday that the network's previous statement about Peters still applies: "Ralph Peters is entitled to his opinion despite the fact that he's choosing to use it as a weapon in order to gain attention. We are extremely proud of our top-rated primetime hosts and all of our opinion programming."

Peters, during Sunday's interview, said that he is not seeking attention or "the chance to be on television. It's because we all need to do our part. These are parlous times."

He said he left Fox News because "as a former military officer who took an oath to the Constitution, I could not be part of a channel that to me was assaulting the Constitution, the constitutional order, the rule of law."

He also said, "I don't want to be the go-to guy for Fox-bashing forever. But what Fox is doing is causing real harm to our country right now."