Perhaps nothing Republican lawmakers do anymore should come as a surprise, but their treatment of Gen. Mark A. Milley on Tuesday opened a new front in the war against civilized norms.

Republicans on the Senate Armed Services Committee didn’t just give a dressing down to the nation’s top soldier about the Afghanistan pullout; they assassinated his character and impugned his patriotism, accusing him of aiding the enemy and of placing his own vanity before the lives of the men and women serving under him.

And this is the man President Donald Trump nominated to be chairman of the Joint Chiefs of Staff, the man who donned fatigues and stood with Trump during his infamous Bible photo op after the gassing and removal of peaceful demonstrators in Lafayette Square.

But now Milley has been portrayed in the Bob Woodward and Robert Costa book “Peril” as reassuring an anxious Chinese military that Trump did not plan to attack China — an undertaking done at the request of Trump political appointees, Milley told the committee.

Sen. Dan Sullivan (R-Alaska) found perfidy in Milley’s de-escalation attempts. “You’re giving a heads-up to the Chinese Communist Party,” he alleged.

After Milley acknowledged he had spoken to Woodward and other authors from The Post and the Wall Street Journal, Sen. Marsha Blackburn (R-Tenn.) accused him of leaking “private conversations with the president,” a charge Milley adamantly rejected.

Unmoved, Blackburn continued: “I think what you did with making time to talk to these authors, burnishing your image, building that bluster, but then not putting the focus on Afghanistan . . . is disappointing to people that have served with you or under you, under your command, and it does not serve our nation well.”

Blackburn, refusing the chairman a response, continued berating him, Central Command’s Gen. Kenneth F. McKenzie Jr. and Defense Secretary Lloyd Austin. “Maybe we’re going to remember you three as the three that broke the military,” she said. “The military was one of the most trustworthy institutions. But in order to get a name in a book, in order to not be drawn into a political fight, what you have managed to do is to politicize the U.S. military.”

The military is broken and no longer trustworthy?

Sen. Josh Hawley (R-Mo.) continued the character assault. “It seems to me you put a high priority on making sure that you were favorably portrayed by the D.C. press corps . . . . Fair enough if that is your priority,” Hawley said, denying Milley a reply.

Hawley suggested this “distracted” Milley from “a rapidly deteriorating, frankly disastrous situation in Afghanistan, which resulted in the death of 13 soldiers . . . . General, I think you should resign.”

Milley, with a chest full of ribbons and bags under his eyes, anticipated that he would hear from senators about his “Peril” portrayal. “I have served this nation for 42 years,” he said in his opening statement. “I’ve spent years in combat, and I’ve buried a lot of my troops who died while defending this country. My loyalty to this nation, its people and the Constitution hasn’t changed and will never change as long as I have a breath to give.”

But Milley may not have appreciated that the merchants of anger on the Republican side of the dais would be competing to see which of them could land an outraged sound bite on “Hannity” or “Tucker Carlson Tonight.”

“The American people are livid.”

“They’re really upset.”

“They’re genuinely pissed off.”

“Really angry.”

In reality, Afghanistan is low on the list of subjects Americans regard as important. Poll after poll shows they don’t think the war in Afghanistan was worth fighting. Most aren’t happy about the chaotic nature of the withdrawal, but 77 percent of Americans supported a pullout, a recent Post-ABC poll found, including 74 percent of Republicans.

Arkansas Republican Sen. Tom Cotton (who last year called for four Army divisions to put down racial-justice protests in U.S. cities) asked Milley why he didn’t resign in protest when President Biden (like Trump) decided against leaving troops in Afghanistan.

“This country doesn’t want generals figuring out what orders we’re going to accept and do, or not,” he replied. “The principle of civilian control of the military is absolute; it’s critical to this republic.”

Had the senators listened, they would have learned from the generals that they uniformly opposed staying in Afghanistan beyond Aug. 31 because it would have resulted in “significant” U.S. casualties, that Trump’s withdrawal agreement with the Taliban was violated by the Taliban from the start and left Afghan security forces demoralized, and that Biden faced the very real risk of the situation escalating into another war if he didn’t withdraw.

But that was difficult to hear much beyond the Republicans’ heckling:

“Humiliation.”

“Fiasco.”

“Debacle.”

“Botched evacuation screwed things up.”

“Disgraceful.”

No. What’s disgraceful is that Republicans have now turned their unquenchable rage into personal attacks on the nation’s military leaders — and on the “broken” and no longer “trustworthy” military itself.