War is divided into two kinds: one that does not follow the rules and one that does.
A war without rules involves using Thirty-Six Stratagems, various deceptive techniques, massacring civilians, flooding cities, launching nuclear bombs, bombing enemy dams, releasing poison gas, and so on—utilizing every means to kill the enemy. The aim is to achieve military victory, which is above all else.
The other kind of war adheres to rules.
In the era of Spring and Autumn, wars between two countries would agree on the location, agree on the number of participants, and notify each other before the battle ensued. When enemies were wounded, they would be allowed to return, and captured elderly would be released.
When the enemy retreated, pursuit was to be symbolic at most, stopping after fifty steps.
Recently, in a certain war, carpet bombing was prohibited as it would harm civilians; attacking civilian infrastructure in cities, cutting off water and electricity, were not allowed.
