Weapons are never the implements of good fortune, and they are to be detested. Therefore, the wise leader avoids them.
Normally the wise leader values patience, but when at war he values action. Since he is opposed to the use of weapons, he uses them only when it is unavoidable, and even then with great restraint.
To praise victory in war is to rejoice in the slaughter of men. The slaughter of men causes grief and sorrow to the people, therefore he who rejoices in this will not be successful.
Fortune follows the restrained, misfortune follows the ambitious.
Therefore victory in war should not be celebrated, but instead should be met with mourning.
(from Tao Te Ching, verse 31, translation by Robert Brookes)