Win or quit, or win and then quit. When Donald Trump was a candidate for president last year, this pretty much represented his strategic menu of options for the country’s ongoing wars. Whichever way things went, they were going to change, though, and for the better. No more putzing around ineffectually with no end in sight.

Backing up these promises were assertions of rare expertise in the management of wars. “There’s nobody bigger or better at the military than I am,” Trump told Fox News in 2015. Senior military officers, with all their medals and campaign ribbons, left him singularly unimpressed. “I know more about offense and defense than they will ever understand, believe me.” And while the sudden emergence of the Islamic State had caught the Pentagon flat-footed, Trump was nonchalant. “I know more about ISIS than the generals do. Believe me.”

How much of this even Trump himself believed is difficult to say. We do know this, however: Since becoming president, he has largely ceded decision-making on the conduct of America’s wars to the very generals he derided while running for office. Trump has not entirely vacated the office of commander-in-chief. Yet, as with so many other aspects of the job, he occupies it on only an occasional basis and rarely with the requisite skill.

Within the armed forces, and among members of the media with a hawkish bent, the beef against Barack Obama as war president was that he micromanaged our military campaigns, denying warriors the latitude and flexibility they needed to get things done. Former Secretary of Defense Robert Gates compared Obama to LBJ, an unrivaled military meddler. He believed that, like Johnson, Obama had intruded into military matters that were beyond his purview, with results that were far from helpful. No one will make a similar charge against President Trump. Not since 1861, when Abraham Lincoln entrusted the conduct of the Civil War to George McClellan, the ineffectual leader known as “Little Napoleon,” has the balance of civil-military authority tilted so greatly in favor of the generals.

When the notoriously risk-averse McClellan proved hesitant about actually committing his army to battle, a caustic Lincoln asked if he might “borrow it for a while,” hinting at the greater presidential assertiveness to come. Barely conversant with history, military or otherwise, Trump himself shows none of Lincoln’s ability to learn and to grow in office. His implicit charge to our own would-be Napoleons reduces to this: Don’t bother me; just get on with it. Trump may preside over America’s ongoing wars. He leaves to others the actual direction of those wars. ...