Which brings us to the conservative narrative of moral equivalence. Often a radical's response to the allegation of a crime by someone deemed unsavory is to respond with some parallel deed for which the U.S. government bears responsibility. Conservatives say this is an error of moral equivalence because the USG are the good guys and the other guys are not. It is wrong to evaluate actors in light of actions because the actors are fundamentally different.
The logic here is precisely backwards, albeit ingenious. Ordinarily we would infer morality from actions. If two parties each commit murder, they are equally wrong. The moral equivalence narrative says we must begin with the implicit assumption that the USG represents the greater good, hence one may not evaluate our enemies by the same standards by which we evaluate ourselves. If we each commit murder, the USG murder deserves at least the benefit of the doubt, if not automatic approval. If the U.S. indulges the use of WMD by Saddam Hussein, our motives are honorable while his are despicable.
However much we love Mom and apple pie, the motivations, effects, and consequences for any policy must stand or fall on their own. Was it really necessary to shoot that last doggie?
The key problem here isn't one of morals, but one of interests- Americans are at least nominally on the same side as the United States Government (USG), so they're almost the good guys by default- no matter how heinous their actions, its those same American asses that they are (supposedly) trying to protect and serve. That creates a powerful incentive to look at the USG in the best possible light in the face of an opponent that threatens said asses, and in no way is the USG so heinous that it can't be defended under those conditions. The coinciding interests naturally generate the "moral equivalency" argument.
On the other hand, this provides a very useful explanatory tool for understanding the difference between American attitudes and the attitudes of those outside the United States. Without that powerful coincidence of interests, it really does come down to Max's inferrence of morals from actions. Even then a case can certainly be made in favour of the USG, but it's much weaker, especially when stripped of the domestic political battles that usually give American foreign policy its shape. The argument against "political equivalence" is much weaker, and criticism of the state can be much more strident. Thus the demonstrable difference between the attitudes of both the American polity and American elites vs. the elites and polity of other allied countries that share much of their basic culture and mores with the U.S. (like England or Canada). It's all about interests, and their influence on the interpretation of relative moral worth, moral authority, and ethical debate.
(Hey, come to think of it, I just argued against a right-wing shibboleth from a Realist perspective. See? Told you it can be done.)