“The first, the supreme, the most far-reaching act of judgment that the statesman and commander have to make is to establish . . . the kind of war on which they are embarking; neither mistaking it for, nor trying to turn it into something that is alien to its nature.” -- Carl von Clausewitz, On War
Also, if you haven't read and internalized Sun Tzu's Art of War or Card's Ender's Game, do so. "The enemy's gate is down."
(A tip of the boonie hat to Irregular Stephen for the link.)