Quote by Hasso von Manstein
"The greatest strategic error is not the plan that fails, but the plan that succeeds at such cost that it prevents future operations."
More from Hasso von Manstein
"The task of the general is to win wars, not battles."
"In war, the moral is half; only the other half is numbers."
"Victory is not final, defeat is not fatal."
"The art of war is simple enough. Find out where your enemy is. Get at him as soon as you can. Strike him as hard as you can, and keep moving on."