Strategy, strategy

Slumming over at the Army War College site, who do I run into but Mark Grimsley. He has a quote in a compilation which appears here on strategy:
Like politics, strategy is the art of the possible; but few can discern what is possible.
This put me in mind of a Lincoln letter quoted by EC Ocean on his site:
Executive mansion, Washington, 21st July, 1863

My dear General Howard:

Your letter of the 10th is received. I was deeply mortified by the escape of Lee across the Potomac, because the substantial destruction of his army would have ended the war, and because I believed such destruction was perfectly easy—believed that General Meade and his noble army had expended all the skill and toil and blood up to the ripe harvest, and then let the crop go to waste. Perhaps my mortification was heightened because I had always believed—making my belief a hobby possibly—that the main rebel army going north of the Potomac could never return, if well attended to; and because I was so greatly flattered in this belief by the operations at Gettysburg.[...]
This is more of an operational gripe, but it has elements of strategic thinking which explain Lincoln's bizarre military management.

Lincoln erroneously believes (in order):

(1) "[S]ubstantial destruction of his army [ANV] would have ended the war."

(2) Destruction of that army was not only possible but in this circumstance "perfectly easy."

(3) Any incursions into the north would invite total destruction of the ANV "if well attended to."

Outside of the Centennial school of ACW history, all of these views have been discredited in detail.

Thus, Lincoln had forgotten, if he ever knew, that the rolls of Lee's army three weeks after Antietam exceeded the returns submitted before the Maryland invasion. Rather resilient, these Rebel organizations, even after a "bloodiest day" record is set.

Lincoln had no rational explanation for Meade's failure to do the "easy" thing. He had no rational story to tell himself about how or why the Rebels "escaped." It made no sense to him, it admitted of no explanation, which is why it enraged him. The mature executive seeks out reasons and weighs them. I have never known an executive who credited the absurd answer. The immature executive, I imagine, lashes out emotionally, driven by demons he cannot control.

Lincoln could not "discern what is possible." Result: his generals - all of them - suffered throughout the war.