As an answer to the question of why Americans are better than Russians, saying that neither Russians nor Americans are equally bad at restraining their country's aggression isn't good.

You could get closer to an answer by counting the corpses.

Ukraine, Chechnya, Syria. Add to that inhuman treatment of civilians, unhinged army, mass rapes as terror means, bombings, chemical attacks, kidnappings, tortures. Putin wins it easily and we in Russia know this well. And he just started.