The point of the treaty
The point of this treaty would be to establish a collective rulebook for how nations that are at war of any kind(1) or in any other state of conflict were weapons are being used by both/all sides of the conflict to inflict damage on the opposing force, should act, what weapons are OK to be used and what weapons are deemed too cruel to be used on other combatants, what to do with prisoners of war, when WMDs(2) are to be used, and any other topics that should be put on the treaty. And finally what to do when a nation(s) breaks this treaty and what sanctions should be bestowed upon them.
Why should rules be put in place
The treaty would aim to stop any excessive damage to civilian infrastructure, places of national/cultural importance, areas of worship, facilities designed for medical use, places of education. The treaty would also aim to limit the amount of suffering faced not only by soldiers but civilians also. Furthermore, clearly define what to do with prisoners of war. Create rules for the uses of WMDs(2).
The importance of why this treaty should be made
War is a disgusting and frightful thing, however it is a necessary evil that must sometimes be used to prevent even greater evils from ever occurring. However war should still have rules. This treaty would help prevent any innocent loss of life and would punish those who do not uphold decency in the face of conflict.
Extra meanings and definitions
-(1) This includes Civil wars, Proxy wars, Wars which involve Guerilla tactics, Ethnic conflicts, Religious conflicts, Defensive Wars and Insurgencies
-(2)Weapons of Mass Destruction. These include Biological, Chemical and Nuclear