(I have taken the main text of this piece from a piece by the ICRC.org
"The rules of war, or international humanitarian law (as it is known formally) are a set of international rules that set out what can and cannot be done during an armed conflict"
and edited it for poetic effect
The rules of war.
All parties must distinguish at all times between combatants and civilians.
(It matters who you kill)
Civilians must never be the target of an attack
(It matters who you kill)
The target must be a military necessity
(It matters who you kill)
Military necessity
an attack or action must be intended to help in the defeat of the enemy
(It matters who you kill)
it must be an attack on a legitimate military objective
(It matters who you kill)
the harm caused to civilians or civilian property must be proportional
a distinction must be made
(It matters who you kill)
Distinction
a principle under international humanitarian law governing the legal use of force in an armed conflict whereby belligerents must distinguish proportionally between combatants. and civilians
(It matters who you kill)
Proportionality
a principle under international humanitarian law governing the legal use of force in an armed conflict
(It matters who you kill)
belligerents must make sure that the harm caused to civilians or civilian property is not excessive and is humane
(It matters who you kill)
Humanity
a principle based in the Hague Conventions which places restrictions against using arms, projectiles
or materials calculated to cause suffering or injury...
(It matters who you kill)
...manifestly disproportionate to the military advantage realized by the use of the weapon for legitimate and honorable military purposes.
(It matters who you kill)
Honour
a principle that demands a certain amount of fairness and mutual respect between adversaries...
(When you kill to these rules
...you do so with honour)
....so it matters who and how you kill
but not that you kill
