Then gave exceptions to rule #6. My point is that IF everyone would obey rule number 6, then there would be no war.

"1) You're allowed to kill in self-defense"
That then implies that the attacker and the defender are not obeying the rule.

"2) You're allowed to kill in the defense of others"
Again, attacker and the defender are not obeying the rule.

"3) Your're allowed to kill other species (this one's impossible to avoid!)"
We do eat the meat of other animals, difficult to avoid but perhaps not totally impossible.

"4) You're allowed to kill enemy soldiers in wartime"
If the enemy soldiers were not allowed to kill you, would you still kill them.
Is this not the same as above where the attacker and the defender are not obeying the rule.

"5) You're allowed to engage in activities in wartime likely to result in the death of innocents, as long as you don't target them specifically."
How does one determine who is innocent and who is not in a war?
Who over rules the rule number 6 ?

"6) You're allowed to kill justly condemned criminals."
If you kill a killer, does that not make you into a killer?