Even though this claim about fighting on behalf of innocent Muslims is dubious (not least because several of our wars, especially the war in Iraq, have killed or led to the killing of hundreds of thousands of these people), it reflects something basic to Americanism. This is the idea that anytime the U.S. fights a war, no matter what the actual reasons for it are, whichever group or nation comes out ahead at the end of the fighting must show eternal gratitude to us. It is apparently an additional requirement that anytime the U.S. fights a war that may benefit some Muslims, all Muslims must similarly be grateful, even if the U.S. wages other wars and backs other policies and governments that harm and kill many other Muslims. In other words, Americanists want Muslims to think like Pan-Islamists when it serves Washington’s purposes (i.e., when it is supposed to make Muslims favorably disposed to us), but Muslims must never think like Pan-Islamists when it doesn’t.
Now clearly, in each of these cases there were non-American beneficiaries. Or, to put it another way, there would also have been costs if the Americans had not intervened. But there is a difference between observing that native populations may benefit from a US military intervention and pretending that this benefit was the sole grounds upon which the United States nobly and selflessly sacrificed its blood and treasure.
One of the prices of imperial protection, after all, is that the dominant power must sometimes sacrifice something himself. So, yes, there's something to the idea of the Heroic Americans Saving the Day, but it's far from the only part of the matter. The trouble with the notion that Americans only fight wars for other people is that it encourages a mindset in which it is much more acceptable for the US to go to war than it is for other countries. Your aggression is wicked, our aggression is the disinterested defence of innocents.
Sometimes, as most obviously, was the case in the Second World War, there really are many innocents to be defended. But the United States was not exactly a disinterested player in World War Two. Nor can one avoid reminding you that the conflict left the United States a much stronger country than it had been before the Japanese dragged the Americans into the war. Self-interest and principle overlapped but even the Good War wasn't quite as clean or noble as is recalled.
And most other conflicts have been much murkier affairs. Indeed, in some you might go so far as to say that the ethical principles involved are so muddied that it becomes important to hype them in order to deflect the accusation that this is a war of choice in which self-interest, not the protection of others, is the real point of the exercise.
Such a calculation flatters the United States' view of itself (just as other great powers have adopted such rationalisations) and there is just enough of a germ of truth in it to give one pause. Nonetheless, when you hear people arguing that the killing is not being done because we want to but because it's needed to protect someone else, you should probably be pretty sceptical.
Remember how in the run-up to the war in Iraq the New York Post thundered against the "Axis of Weasel" and those feeble euros in France and Germany? Remember how they screamed how disgraceful this ingratitude was when the bodies of so many young Americans lie cold in european clay? If there's a statute of limitations upon martial tribute and gratitude then, in this reading at least, it hasn't expired yet. Oddly, the very people most likely to deny the existence of an American Empire are also the people who demand fealty from the allies and vassal tribes to which it has so generously offered protection.
Few people in western europe forget the American sacrifice in the war, and fewer still - least of all me - would deny its reality. But it was never the disinterested kind of project some tellings of the story might lead you to believe. And nor, of course, have the other wars since. Self-interest and principle overlap from time to time, but only occasionally and only rarely completely. There's little wrong with recognising this reality, not least since doing so might permit one to assess the wisdom of the next war more accurately than we* have those we're currently figthing.
*By which I also (or mainly) mean, for sure, me.