To behave as barbarians because barbarians do is to become barbarous.

If the contest is to determine who can act the worst, then by all means we should follow their rules.

An aside: When my dad was in the Army, he was assigned to guard German prisoners of war in Texas. He told me that the guards spoke to the prisoners, generally, a little more than they ought to: not so much that they compromised security, but more because they were all fellow human beings. (He pointed out that these were all Wermacht prisoners, regular soldiers, and not SS.) The prisoners liked to talk about their homes and their families, whom they had great hopes of seeing again. Dad recalled especially that the prisoners were all very very happy to have been captured by Americans rather than Russians, and that many of them had surrendered when, had they faced Russians, they would have fought on. The Germans expected to be mistreated and even tortured by the Russians, and probably shot anyway, so the thought was to fight on even in desperate circumstances. They expected to be treated decently by the Americans, so the incentive to fight on, especially near the end of the war, was considerably less.

As you may be aware, American troops captured by SS units near the end of the war often faced summary execution. Our military and political leadership of the time felt no need to follow their example and play by their rules, and yet won the war anyway.

What happened to all those German prisoners? They went home, and they remembered that Americans were decent and honorable people. Of such memories is peace made, rather than a sullen and resentful armistice based on who has been more successfully brutal.

I had thought to go to the Gospels for Mark 8:36, "For what shall it profit a man, if he shall gain the whole world, and lose his own soul?", but that probably doesn't speak to you. So let's try this one: "For they have sown the wind, and they shall reap the whirlwind: it hath no stalk: the bud shall yield no meal: if so be it yield, the strangers shall swallow it up." Hosea 8:7