Modern wars are seldom fought without hatred between nations; this serves more or less as a substitute for hatred between individuals.
Carl von ClausewitzThe 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 ClausewitzBy 'intelligence' we mean every sort of information about the enemy and his country - the basis, in short, of our own plans and operations.
Carl von Clausewitz