"If you believe in moral absolutes and know that there is a difference between good and evil, the answer is most certainly YES"
--- Whose set of moral absolutes is more important?
It can be demonstrated that Western Civ's moral absolutes include a high value on life, even of our enemies.
It can also be demonstrated that the terrorists moral absolutes do not include this high value, at least with respect to their enemies.
How do you "prove" which set of moral absolutes is correct?
Especially since both as reverenced as being direct from that cultures diety.
"We hold these truths to be self-evident"---to anyone with a conscience.
I do not think that a "proof" can be derived like a mathematical theorem, if that is what you are looking for. There is really only one moral culture whose values have withstood the test of millennia.