The only way a war, or violence in general, can effectively resolve a dispute is if both parties agree upon the terms.
The reason for this is that without such an agreement, one side or the other will simply continue to fight until complete annihilation of the enemy (or themselves) has occurred.
When such agreement exists, even if it is only a loose correspondence of concepts, wars are fought until some level of military incapacity on one side, which then surrenders to prevent further useless destruction, and also to improve conditions imposed in the armistice.
Under many conditions, this observation goes without saying to the point where it seems absurd to state it.
However, it is in the breach that it is more relevantly observed. When two warring factions have widely disparate goals or strategic positions, the definition of "winning" or "losing" is so different for each side that a formally recognizable end to the conflict under the terms it is engaged in cannot be reached. Examples of wars like this might include proxy civil wars, like Viet Nam, wars of colonization or occupation, such as the Soviets experienced in Afghanistan, or wars of liberation where there is no clear oppressor (like a foreign power) to overthrow. Many conventional civil wars also pose this problem.
In any war where at least one side views the conflict as a "total war", the issue is moot since the "rules" state that the war is not over until one side is annihilated. Some of the battles described in the Old Testament fit this model - wars where even a single survivor will not yield until death, imprisonment, or inslavement.
So called "modern war," as developed in Europe over the last millennia or so, is an example of an attempt to move back from wars of total destruction, by loosely agreeing on what terms a conflict is deemed to be hopeless for one side and thus justify surrender and the acceptance of terms. This might be as simple as when one's army is so outnumbered or outgunned that they "run away, run away". It could be as abstract and technical as the capture of a special flag, or being capable of imposing a mortal threat upon their general or king (cf., the rules of chess).
Under such general agreements, and given a reasonably similar degree of warmaking technology, battles can be fought between nations or cities without destroying much of the civilian infrastructure. This could be to resolve a diplomatic dispute, including fighting over lands or wealth.
When the technical abilities of the two sides are heavily lopsided, under these rules a war would seem to be over before it has begun. However, and rather ironically, enough of a disparity here will tend to change the battlefield rules so much that the fighting changes character completely. For instance, modern high technology is amazing in its ability to rain death and destruction down from the sky. This amazing air power, however, cannot take and hold even a small agricultural village. The lower the technology of the people on the ground, the easier it is for them to resist and survive relatively intact.
The obvious and most absurd example of this is when an army has the ability to use nuclear armaments. While promising up to complete annihilation, and a terrifying weapon, in the end they are basically useless - like the old total wars, that ended with the salting of the fields and poisoning of the wells, they do not settle an issue or gain territory or wealth - they simply destroy it and render in uninhabitable. (There does remain, however, the awful question of whether an area blessed with rich oil fields could still be exploited for its resources even after the lands themselves have been scorched and irradiated so as to be barren).
© Huw Powell