No doubt a hubbub is just beginning in respect of whether President Obama made the right move in trading for Sergeant Bowe Bergdahl five members of the Taliban whom we’d been holding at Cuba. A reporter of the McClatchy newspapers is quoting a joint statement by the chairman of the Armed Services Committee in the House and the ranking member of the Senate Armed Services Committee as saying that Mr. Obama “chose to ignore the law” when he cut the deal with the Taliban.

It happens when this news broke we’d just come from a book party for the ex-prosecutor-turned-columnist Andrew C. McCarthy, whose book about building a political case for President Obama’s impeachment has just been brought out by Encounter. The book, “Faithless Execution,” is a devastating indictment of Mr. Obama’s seeming indifference to the law — even though the oath he must take before entering into his duties requires him to faithfully execute the office of President and preserve, protect, and defend the Constitution.

Yet we would be careful about going after Mr. Obama in respect of the prisoner exchange. The law, according to the newspaper reports, requires the president to notify Congress thirty days in advance before he can pull someone out of Guantanamo. But where did Congress get the authority to try to micromanage prisoner releases? Mr. Obama’s aides are citing the President’s prerogatives as commander-in-chief. The fact is that once war has begun, those prerogatives — powers — are enormous. Way underestimated, in our view.

The commander-in-chief clause is the only clause President Lincoln ever cited for his authority to free the slaves. He marked the point in in 1863 in a letter he sent to a crony, James Conkling. The letter was designed to be read at a rally in Illinois. “You dislike the emancipation proclamation,” he wrote, “and, perhaps would have it retracted. You say it is unconstitutional. I think differently. I think the constitution invests its commander-in-chief, with the law of war in time of war.”

“The most that can be said, if so much,” Lincoln continued, “is that slaves are property. Is there — has there ever been — any question that by the law of war, property, both of enemies and friends, may be taken when needed? And is it not needed whenever taking it, helps us, or hurts the enemy? Armies, the world over, destroy enemies’ property when they can not use it.” Lincoln had freed only those slaves in the rebellious states.

It strikes us as a stretch to suggest that under the commander-in-chief clause a President of America could free the slaves in the rebellious states but could not spring five members of the Taliban from our own prison. We understand that the slaves are innocent and the Taliban are guilty. But we are in a war, and how to get our prisoners back from the enemy is a judgment call of exactly the kind a chief commander is constitutionally set up to make.