To 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 ClausewitzNo other human activity is so continuously or universally bound up with chance. And through the element of chance, guesswork and luck come to play a great part in war.
Carl von Clausewitz