Well again I think that you are overreacting - I think that is not really true at all. It is a quite minor incident and very soon the only people that will be chiming in about will be the hard Left. You are being quite melodramatic here, IMO. As for "living up to our ideals" all I can say if you expect everyone to live up to "our ideals" or that if some bad apple fails to "live up to our ideals" that means the we have collectively failed to do so then all I can say is that you and I have a rather different notion of what our "ideals" are about, not to mention what society is about. We have lawbreakers in civilian life - does that mean that we collectively "fail our ideals?"
In history people will scratch their heads over the concern given this incident. The Euros (I am talking about the Dutch and the Germans) could not even get out of their barracks to protect civilians and at least 2,000 of them died. You do not seem very upset about this. I think that you exaggerate this.
Does it make it harder for the troops in the end? That is an open question. It may intimidate more people for all we know. What does make it harder is the reaction to this by the left. It give the opposition the notion that they can turn this into another Vietnam. That </I. is what is dangerous.
Luckily the American population see the whole thing for what it is.