Everything in strategy is very simple, but that does not mean everything is very easy.
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 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 ClausewitzLastly, the great uncertainty of all data in War is a peculiar difficulty, because all action must, to a certain extent, be planned in a mere twilight, which in addition not unfrequently — like the effect of a fog or moonshine — gives to things exaggerated dimensions and an unnatural appearance.
Carl von ClausewitzIf we consider the actual basis of this information [i.e., intelligence], how unreliable and transient it is, we soon realize that war is a flimsy structure that can easily collapse and bury us in its ruins. ... Many intelligence reports in war are contradictory; even more are false, and most are uncertain. This is true of all intelligence but even more so in the heat of battle, where such reports tend to contradict and cancel each other out. In short, most intelligence is false, and the effect of fear is to multiply lies and inaccuracies.
Carl von Clausewitz