The art of war is of vital importance to the state. It is a matter of life and death, a road either to safety or to ruin. Hence under no circumstances can it be neglected.
Hence it is only the enlightened ruler and wise general who will use the highest intelligence of the army for purposes of spying, and thereby they achieve great results. Spies are the most important element in war, because upon them depends an army's ability to move.
Supreme excellence consists in breaking the enemies resistance without fighting.
If you know the enemy and know yourself, you need not fear the result of a hundred battles.
In all history, there is no instance of a country having benefited from prolonged warfare. Only one who knows the disastrous effects of a long war can realize the supreme importance of rapidly bringing it to a close. It is only one who is thoroughly acquainted with the evils of war who can thoroughly understand the profitable way of carrying it on.
* as channeled by James Clavell