Daodejing Chapter 30: a necessary evil

A ruler nurtured by the Dao
Never uses the force of arms
Against all-under-heaven.
It is sure to rebound.
Wherever armies have camped,
Brambles and thorns grow wild.
After a great war,
Years of famine follow.
The best general
Focuses on achieving results,
Not winning by force.
He achieves results
Without bragging,
Without boasting,
Without pride.
He achieves results
With reluctance,
Without force.
Brute force ages quickly.
It goes against the Dao.
Going against the Dao
Leads to an early end.

「以道佐人主者，不以兵強天下；其事好還。師之所處，荊棘生焉！大軍之後，必有凶年。善者果而已，不敢以取強。果而勿矜，果而勿伐，果而勿驕。果而不得已，果而勿強。物壯則老，是謂不道，不道早已。」

Laozi was appalled by the destruction and suffering caused by the countless wars that took place between the various feudal states battling for dominance of China towards the end of the Spring and Autumn period.

But rather than attempting to persuade the ruling class to give up war for moral and ethical reasons, he takes a much more pragmatic approach by pointing out that rushing into a conflict will hurt them just as much as (if not more than) their opponents because it will cause them to age quickly and lead to an early end.

Laozi therefore counsels that good generals focus on achieving results in the most effective way possible — preferably without using force. Ultimately, if they have no choice but to enter into a conflict they should bring it to an end as soon as their objective is achieved and take all the necessary steps to minimize the losses on both sides.

At best war is a necessary evil. Victory is not a cause for celebration or jubilation. Resorting to force is a sign of weakness and failure rather than strength and success. It only leads to brambles and thorns.

Note
I took this image at Longhu (Dragon Tiger) Mountain, a famous Daoist site about ten miles south of Yingtan in Jiangxi Province. A great place to visit!