The bible plainly states not to kill
Does it really?
"go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass." - 1Samuel 15:3
Saul actually got rejected for not killing enough Amalekites and this was in revenge for something a previous generation of Amalekites had done centuries earlier. How would yo feel about committing genocide because of what the gggggggrandparents of another nation had done?
Why do you get think the bible is a useful source of ethics?
if all people would listen there would be no wars
But some people commit terrible atrocities against other nations - Syria for example. How can it be ethical to sit back and do nothing?
It would be intersting to know what teachings of JWs you agree with. Perhaps you could tell us on another thread. Is it their shunning of family members, their failed prophecies or something else?