No one starts a war--or rather, no one in his sense ought to do so--without first being clear in his mind what he intends to achieve by the war and how he intends to conduct it.
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 ClausewitzIf the enemy is to be coerced, you must put him in a situation that is even more unpleasant than the sacrifice you call on him to make. The hardships of the situation must not be merely transient - at least not in appearance. Otherwise, the enemy would not give in, but would wait for things to improve.
Carl von Clausewitz