It is odd and even shocking to see a Republican president get crosswise with the U.S. military.

During the post-Vietnam era — and through the War on Terror years — GOP politicians have made pro-troop hawkishness a key element of the party's identity. Ronald Reagan oversaw one of the largest peacetime military buildups in U.S. history. When George W. Bush ran for president in 2000, his running mate Dick Cheney told the Republican National Convention that "help is on the way" for the armed forces. Donald Trump followed in the path of his predecessors, promising in 2016 to "rebuild" the military — and then, after taking office, installed several retired generals in his Cabinet. If Republican leaders ever had a negative thought about the armed forces in recent decades, they stayed mum. Publicly, they always allied themselves with the troops.

Until Monday, that is.

That is when President Trump — under fire for The Atlantic's recent story alleging he had made disparaging remarks about service in the armed forces — accused the country's military leaders of waging wars to profit defense contractors.

"I'm not saying the military's in love with me," Trump said. "The soldiers are, the top people in the Pentagon probably aren't because they want to do nothing but fight wars so that all of those wonderful companies that make the bombs and make the planes and make everything else stay happy."

Now, there are reasonable discussions to be had about America's massive defense spending and the country's warmaking. And it is true that many generals find comfortable sinecures in the armaments industry in their retirement years. But Trump, who has spent this election season touting his administration's increase to the military budget, is in no position to make the critique. Instead, what his comments on Monday really indicate is how rattled he is by The Atlantic's report — and how desperate he is to find a scapegoat. But the tension between Trump and military leaders has deep roots.

Trump doesn't understand the culture of the American armed forces. Trump may say publicly that he loves the military, but what he really seems to admire is a show of strength, and even violence. He delighted in then-Defense Secretary James Mattis' "Mad Dog" nickname, promoted the use of torture against prisoners of war, gave pardons to service members accused or convicted of war crimes, and relaxed the rules of engagement for forces in Afghanistan. The president also loves to bask in the glory of a little bit of spit-and-polish pomp: His 2019 "Salute to America" military parade was prompted by a case of Bastille Day envy.

It is the military's job to be prepared to inflict great harm on the country's enemies. But American military culture emphasizes discipline and honor. Every soldier, marine, sailor, and airman takes an oath to "support and defend the Constitution of the United States." Cadets at the nation's military academies, which educate many future generals and admirals, are governed by an honor code. Adultery is a criminal offense under the Military Code of Justice. Those institutional values — which are completely in contrast to how Trump speaks and acts — are why so many current and former officers spoke out against his desire to use the military against protesters this summer.

He is incoherent on matters of war and peace. Publicly, at least, the president wants to have it both ways. His party spent its convention making the case that Trump had kept the United States out of "endless foreign wars." The U.S. military footprint abroad isn't really any smaller than when he was inaugurated, however, and Trump's actions — killing a top Iranian general, ending the nuclear accord with that country, ripping up arms control agreements with Russia, and moving to an increasingly confrontational stance with China — have actually moved the United States closer to a major conflict. Trump has tried to withdraw troops from Syria and end the war in Afghanistan, only to be stymied by opposition from the military and hawkish allies like Sen. Lindsey Graham (R-S.C.) Those confrontations have helped fuel the tension between the president and service leaders.

Actually, "the soldiers" may not love him so much. Even before The Atlantic story was published, Trump's approval among the troops appeared to be slipping. A Military Times poll of more than 1,000 active-duty service members showed "a slight but significant" tilt toward former Vice President Joe Biden in the coming presidential election. And nearly half of respondents had an unfavorable view of the current president.

Throw in a few other scandals, old and new — Trump's deferments during Vietnam, his inaction in the face of reports of Russian bounties against American troops — and it's not hard to see why the relationship between the military and the president seems to be souring.

A more deft politician would try to patch up the relationship, or at least smooth over the rough parts. We know, though, that Trump's first instinct when criticized — perhaps his only instinct — is to attack the critic. For several generations, the Republican Party has made every effort to ally itself with America's armed forces. President Trump might be ready to burn that relationship down.

Want more essential commentary and analysis like this delivered straight to your inbox? Sign up for The Week's "Today's best articles" newsletter here.