President Donald Trump on Friday cleared three military service members of war crimes, even after being reportedly advised against doing so by Defense Secretary Mark Esper and Army Secretary Ryan McCarthy. Mr. Trump interceded on behalf of Army Maj. Mathew Golsteyn, who had been charged with murdering an Afghan man; Edward Gallagher, a Navy SEAL who was convicted in connection with posing for a photo with the corpse of a fighter in Iraq; and Army First Lt. Clint Lorance, who, after nine fellow unit members testified against him, had been convicted of murdering two civilians in Afghanistan.

Mr. Trump may believe that intervening pays respect to those who have served in uniform, that it shows he’s “pro-military.” But if this is his view, he’s wrong. In reality, Mr. Trump’s meddling undermines the military’s institutional values, risks endangering American service members, and disrespects the honorable service of the overwhelming majority of veterans.

The military strives to ensure that its members adhere to the laws of war and respect human rights. Service members are trained, for example, to avoid civilian casualties by understanding rules of engagement and following the proper steps for escalation of force. They also learn the appropriate ways to treat detainees, and interrogators are trained to employ only the approved, legal methods.

During my two deployments to Afghanistan, my intelligence work helped lead to the capture of insurgent leaders. Sharing responsibility for their capture and as a recipient of the intelligence produced by their interrogations, I had a sense of moral reassurance in the understanding that my colleagues handled and interrogated the detainees humanely — just as they had been trained.