A general in time of war is constantly bombarded by reports both true and false; by errors arising from fear or negligence or hastiness; by disobedience born of right or wrong interpretations, of ill will; of a proper or mistaken sense of duty; of laziness; or of exhaustion; and by accident that nobody could have foreseen. In short, he is exposed to countless impressions, most of them disturbing, few of them encouraging. ... If a man were to yield to these pressures, he would never complete an operation.
Carl von ClausewitzIf we do not learn to regard a war, and the separate campaigns of which it is composed, as a chain of linked engagements each leading to the next, but instead succumb to the idea that the capture of certain geographical points or the seizure of undefended provinces are of value in themselves, we are liable to regard them as windfall profits.
Carl von ClausewitzRather than comparing [war] to art we could more accurately compare it to commerce, which is also a conflict of human interests and activities; and it is still closer to politics, which in turn may be considered as a kind of commerce on a larger scale.
Carl von ClausewitzHowever much pains may be taken to combine the soldier and the citizen in one and the same individual, whatever may be done to nationalize wars, never will it be possible to do away with the professionalism of the business; and if that cannot be done, then those who belong to it will always look upon themselves as a kind of guild, in the regulations, laws, and customs in which the "Spirit of War" finds its expression. It would be very wrong to look down upon this corporate spirit, or esprit de corps, which may and should exist more or less in every Army.
Carl von ClausewitzIn short, absolute, so-called mathematical, factors never find a firm basis in military calculations. From the very start, there is an interplay of possibilities, probabilities, good luck and bad, that weaves its way throughout the length and breadth of the tapestry. In the whole range of human activities, war most closely resembles a game of cards.
Carl von Clausewitz