In the spats between President Trump and the various now-retired brass, The New York Sun is on the side of the commander in chief. It’s one thing for generals and admirals to use their retirement to enter the political fray and criticize the — or any — president. Fair enough. It’s another to expect to be able to do so without taking some flak. In politics, too, that comes with the territory.

Feature General Stanley McChrystal. He is up on the Drudge Report for using the word “disturbing” to describe Mr. Trump’s behavior toward the military. Mr. Drudge links to a discussion on ABC News, in which General McChrystal is drawn out by Jonathan Karl, who asks the general what to “make of a leader” who speaks the way Mr. Trump did of Admiral Wm. McRaven.

That was a reference to Mr. Trump’s jibe about how it would have been “nice” had Osama bin Laden been killed earlier. The President implied that the long time to find and get bin Laden was somehow the fault of Admiral McRaven, who was the commander over the Navy Seals who, in 2011, slew the leader of al-Qaeda. It was a shocking retort in respect of an exemplary admiral.

The key political point, though, is that it was Admiral McRaven who drew first, so to speak, blood. He co-authored for the Washington Post an op-ed accusing Mr. Trump of, among other things, having “embarrassed us in the eyes of our children, humiliated us on the world stage and, worst of all, divided us as a nation.” Where does it become inappropriate for the President to respond?

In context, Mr. Trump’s riposte to Admiral McRaven struck us as mild. It was not Mr. Trump who divided America. It was already divided when he threw into the ring his hat. It was not Mr. Trump who let the Russians enter the Middle East, stood down while Red China built its bases in the South China Sea, and lost control of the Mexican border. Or characterized a quarter of Americans as “deplorables.”

The worst that can be said of Mr. Trump (and it’s no small thing) is that he has failed to unify our country. In that, however, he is in distinguished company, including his three predecessors. One of them, President Obama, relieved General McChrystal of command, ending his glorious career in uniform, because of all the griping in his camarilla about the president.

So where — in a country that cherishes civilian supremacy over the military — does General McChrystal come off lecturing the constitutional commander in chief on leadership? The general dismisses Mr. Trump’s protests that he’s begun rebuilding the military budget. The general suggests that’s not the measure of support for the military. Not the only one, we’d suggest, but one.

The importance of all this lies in the remarkable position of our military. The point was beautifully made by Harvard’s president, Drew Faust, in a speech at West Point. Our military, she noted that Gallup has found, is the last institution in which Americans repose high confidence. “Not organized religion, not government, not newspapers, not banks,” she told the Cadets. “You. You and all you represent.”

In our estimate, the respect our military enjoys was achieved by deeds in combat and comportment in peace — and a preparedness to stand apart from politics. The more sordid our politics, the sharper the glory in which our military emerges. No reason for our retired generals not to enter the political fray. The art of that deal, though, is to understand the new arena for which they shed the uniform.