The deduction of effect from cause is often blocked by some insuperable extrinsic obstacle: the true causes may be quite unknown. Nowhere in life is this so common as in war, where the facts are seldom fully known and the underlying motives even less so.
Carl von ClausewitzAction in war is like movement in a resistant element. Just as the simplest and most natural of movements, walking, cannot easily be performed in water, so in war, it is difficult for normal efforts to achieve even moderate results.
Carl von ClausewitzThe world has a way of undermining complex plans. This is particularly true in fast moving environments. A fast moving environment can evolve more quickly than a complex plan can be adapted to it. By the time you have adapted, the target has changed.
Carl von ClausewitzTo discover how much of our resources must be mobilized for war, we must first examine our political aim and that of the enemy. We must gauge the strength and situation of the opposite state. We must gauge the character and abilities of its government and people and do the same in regard to our own. Finally, we must evaluate the political sympathies of other states and the effect the war may have on them.
Carl von Clausewitz