You don't know that. What we ought to know is why we do what we do. Moral authority? Not in the last 40 years.
Moral authority in regard to matters of freedom and self-government.
Of course, you may be one of those ultra-social conservatives who think we "asked for" 9-11 due to moral decline. But even they can't deny that we still have some right to judge other countries with respect to freedom and self-government. That fact that you try to deny this suggests that you don't have much respect for your country.
You sound like a standard-brand liberal, and an especially dumb one, at that.