Fox News host Tucker Carlson in New York in March 2017. (Richard Drew/AP)

There’s a cost to all the ranting that Sean Hannity and Tucker Carlson do on Fox News during prime time every night. Of course, their most prominent victims are the truth and reasoned discussion. But for Fox News, there’s a more immediate one: The alienation of folks such as retired Army Lt. Col. Ralph Peters. As BuzzFeed reported on Tuesday afternoon, this Fox News contributor is bailing.

Peters wrote an email to colleagues that didn’t manage to stay within the confines of the organization:

“In my view, Fox has degenerated from providing a legitimate and much-needed outlet for conservative voices to a mere propaganda machine for a destructive and ethically ruinous administration. When prime-time hosts — who have never served our country in any capacity — dismiss facts and empirical reality to launch profoundly dishonest assaults on the FBI, the Justice Department, the courts, the intelligence community (in which I served) and, not least, a model public servant and genuine war hero such as [special counsel Robert S. Mueller III] — all the while scaremongering with lurid warnings of ‘deep-state’ machinations — I cannot be part of the same organization, even at a remove. To me, Fox News is now wittingly harming our system of government for profit.”

Peters served as a contributor at Fox News for about a decade, opining on issues relating to the military, intelligence, North Korea and beyond. Not long ago, he inveighed against President Trump’s proposal for a military parade in the United States. “I served in the military for almost 22 years, enlisted man and officer. Let me tell you: I value our tradition of civilian control of the military. . . . I don’t like the image of heavy weapons parading through our streets and the streets of American cities. . . . We would throw the training schedules out the window.”

Far more contentious was an appearance last year on “Tucker Carlson Tonight,” in which the host argued that Russia’s Vladimir Putin — while being a bad guy — can share interests with the United States, including in the fight against the Islamic State.

Peters: You sound like Charles Lindbergh in 1938 saying [Adolf] Hitler hasn’t attacked us.

Carlson: I beg your pardon? You cannot compare me to somebody who makes apologies for Hitler. And I don’t think Putin is comparable.

Peters: I think Putin is.

Carlson: I think it is a grotesque overstatement actually. I think it’s insane.

Peters: Fine, you can think it’s insane all you want.

Carlson: You just up compared me to a Nazi apologist because I asked a simple question. Which is, why does it contravene American interest with a common cause with a group trying to kill ISIS?

Peters: He invaded his neighbors, broken the long peace in Europe, he assassinates dissidents and journalists, he bombs women and children on purpose in Syria, he is as bad as Hitler. If you don’t like the Charles Lindbergh [comparison] — I will retract that, but you sound like someone in the 1938 saying what has Hitler done to us?

Good cable television, in other words. Peters has a history of speaking his mind as the cameras roll. Back in 2015, on Fox Business Network, he called President Barack Obama a “total pussy” for his antiterrorism policies. He was suspended for the outburst.

In his goodbye email, Peters wrote: “Four decades ago, I took an oath as a newly commissioned officer. I swore to ‘support and defend the Constitution,’ and that oath did not expire when I took off my uniform. Today, I feel that Fox News is assaulting our constitutional order and the rule of law, while fostering corrosive and unjustified paranoia among viewers. Over my decade with Fox, I long was proud of the association. Now I am ashamed.”

Fox News issued this statement: “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 prime-time hosts and all of our opinion programming.”

In a chat with the Erik Wemple Blog, Peters, 65, said he couldn’t speak out about his time at Fox News because his contract hasn’t yet expired. He was careful to credit the hard news people at the network, drawing a hard line between them and the opinion folks in prime time.

Peters did, however, address Fox News’s criticism of his email: “It just makes no sense. If I wanted attention, I would have stayed on Fox News and spoke to a few million people a day. I have no intention of seeking other TV news opportunities. I am not a great-looking guy, I have a high-pitched voice, and I smack my lips. To what end am I looking for attention?” Also: Peters said that the farewell email that leaked to BuzzFeed “was meant for internal consumption. Fox is entitled to their views.”