>100 is my answer
We both know that it is not true. Because by this logic, you wouldn't fire a weapon at someone who is about to stab your wife or child. Because there is a small chance that they will die of a heart attack before they can do it. So it is some value that is < 100%, but apparently that is not good enough for you.
You did not accept my answer and did not answer to mine as well.
On top of that, while you are pulling some hypothetical scenarios, the reality is exactly as I described. Governments, especially us gov, kept invading, bombing and killing people based on some subjective percentages and this is still ongoing.
Although you did not like my ‘prefer to die instead of kill’ idea, you still did not solve ‘you can kill everyone since there is a chance anyone can kill you’ problem. And reality is closer to latter, unfortunately.