The Art of War by Sun Tzu

II Waging War

7. It is only one who is thoroughly acquainted with the evils of war that can thoroughly understand the profitable way of carrying it on.

8. The skilful soldier does not raise a second levy, neither are his supply wagons loaded more than twice.

Notes by Zephyrist:

In warfare evil men flourish. Evil flourishes in chaos and the general populace always suffer.Sun Tzu states that anyone that has seen the full horrors of war knows this truism.

In the second paragraph Sun Tzu goes back to labouring the same point in a different way. A good warrior only needs one levy of soldiers to win and only one set of supplies. Presumably because the good warrior has chosen his perfect moment with the perfect strategy to get it right first time and secure victory.