I wrote this in a SelectSmart debate forum that seems to have disappeared, so I'm going to preserve it here:
I am always amazed at the popularity of moral relativism among Americans, and I can't help but wonder if that is why we are so docile in the face of injustice and so unwilling to critically examine the rightness or wrongness of our actions as the most powerful nation in the world.
I admire Noam Chomsky's elegant phrasing of the Golden Rule: "If an action is right for us, it is right for others; and if wrong for others, it is wrong for us. Those who reject that standard simply declare that acts are justified by power."
Denying that there are moral absolutes is very convenient when you're the most powerful kid on the block. It allows you to justify whatever action you want to justify and still feel good about yourself. It means you don't have to worry about whether your behavior (or your society's behavior) is right or wrong. Since there's no objective standard, there's no way to make such a determination anyway. The result is that by default power becomes the standard. In any serious moral conflict, might makes right.
Since no one can challenge the might of the United States, moral relativism is very convenient for Americans right now. I view its popularity in that context.