One of the less edifying features of our current public discourse is the tendency to say "shut up!" by accusing someone of postulating moral equivalence between, say, ourselves and the terrorists who have attacked us.
Now it is doubtless true that many critics of the Administration's follow-up to 9-11 really are attempting to draw a moral equivalence, or even worse, to displace moral blame for the attacks from those who carried them out to someone else. Certainly that is a dominant theme on the political Left, and the "Truther" phenomenon is its natural manifestation. If we are morally to blame then we must be the ones who actually did it, a priori: no matter how much people try to cling to the idea that we are responsible for outcomes rather than for our own acts, nature reasserts herself. The "Truthers" are just being more consistent with the reality of how moral responsibility works than other factions of the "blame America first" mob.
[Note to the paleo Right: if you don't want to be like the Truther Left, then don't be like them. You can choose.]
Now it would of course be very convenient for the administration hawks and their agitators if everyone who criticizes administration policy were drawing a moral equivalence or blaming America first. But about this the hawks are kidding themselves. Because in point of fact it isn't our job, as ourselves, to make moral evaluations of our enemies (those not yet vanquished) at all. It is our job to make moral evaluations of ourselves; and to understand what we expect our enemies to do so that we can make prudent decisions, the making of prudent decisions also being our moral obligation. The required moral evaluation is all about us, and moral evaluation of them doesn't enter into it. We need to know what to expect from them in terms of behavior. Our expectations about their behavior reflect on what we should and should not do morally and practically. That's it, until such time as the particular enemy in question has been vanquished and is either dead or on trial.
So when we use the language of cause in reference to ourselves we are talking about something quite different from what we are talking about when we use the language of cause in reference to our enemies. The things that we do must be morally justified; the things they do must merely be understood. Understanding is not justification, and shouldn't be confused with justification. It would be grossly immoral for us to march into a nest of vipers and unleash all manner of death and mayhem without all the usual prudential considerations being taken into account. This is true even if occasionally a viper enters our camp and kills one of our young: if dealing with the nest is beyond our morally-realizeable capabilities then we are left to dealing with keeping incursions as isolated - and yes, unprovoked - as possible.
The prudential - but no less morally binding for being prudential - requirement not to provoke the nest of vipers doesn't make us morally equivalent to the vipers. Our expectations of what they will do is part of the prudential evaluation of our own acts. But it doesn't say anything at all about them morally: apples are not oranges, and expectation is not justification.
We don't have to justify what they do. We only have to justify what we do. No amount of outrage that God has allowed the serpent to dwell on this same earth with us can turn an apple into an orange.