I think Carl von Clausewitz would beg to disagree. For him much of warfare before the Seven Years War was trapped in a stifled, gamelike state, with commanders enamoured over pretty, overcomplicated manoeuvres, and troops killing each other over trifling matters - ultimately it was the toy of Princes, Prime Ministers, and their cabinets. What the Seven Years War, and especially the French Revolution, did was free War from these artificial constraints, shifting from Cabinet War into National War, where the job of the Commander-in-Chief in combat was to husband, and at the right moments unleash, his army's moral force, and where the army fights for ends which furthers the Nation. I suggest you ask the conscripts of Russia and the guerrillas of Spain whether or not the kind of War they fought was short and separated from the affairs of government and civilian life. As for nobility, Clausewitz finds some nobility in what he calls the military virtues (defined as the ability, earned by experience, to last hours in the thick of the fight, with cannonballs and shot cutting down the comrades around you, without succumbing to terror or exhaustion) but he makes it clear that War, even the gamelike war before the SYW, is not truly a game, it is deadly serious and any "gentlemanly conduct" only serves to delay the arrival of Peace, and is thus morally reprehensible.