You claim that "authenticity is a bullshit concern," but it seems to me that authenticity is your primary value, the core of what you want from a photograph depicting violence, horror, or war. I certainly can't think of what else to call the thread that binds the images you cite as having moved you. And despite what you seem to think, "authenticity" doesn't mean realism, but rather an absence of mediation, a direct conduit between what is depicted and your eyes. An "authentic" photograph could be taken by a surveillance camera. Certainly intention is irrelevant, especially since you bring up the lynching postcards in Without Sanctuary, which were made for the scum who cheered the lynchings to bring home as trophies. What you seem to want is a naive or inanimate eye behind the camera, an agent with no sense that a photograph is anything but a bald record of what transpires in front of the lens.
It's true that the most moving things in photographs are details that are apparently incidental, sometimes subliminal, maybe even invisible to the photographer, that occur beyond any calculation, and that can be recorded equally by Cartier-Bresson or by a tourist with a point-and-shoot. That kind of detail is what Roland Barthes called the punctum—the thorn in a picture that snags you. It can be a face deep in the background of a shot, or the merest hint of vulnerability in the body language of an otherwise self-possessed subject. In this picture, an anonymous postcard, circa 1915, of an incident during the Mexican Revolution, the punctum is not the obvious—the man about to be executed—or even the inert body behind the spectators at left. Rather, it resides in the legs of the members of the firing squad: the low butts, the cheap pants, the unsoldierly splayed stances—the evidence that they are just a bunch of farmers, taking no more pleasure in their task than they would in putting down a sick cow. That note of human frailty flattens the drama and shows war for what it is: necessary in the view of both sides, maybe, but ultimately futile and as tedious as it is horrible. The picture was taken by a gringo entrepreneur who probably didn't give a toss who won the war. His stateside customers, to whom Mexican lives were not quite real, bought it for a thrill that can accurately be described as pornographic.
That humble detail is also what makes the picture a small work of art, I think, regardless of the photographer's intention or awareness. In photography, where matters creep into the frame of their own accord, a work can sometimes be more intelligent than its maker. The picture certainly fits my idea of art a whole lot more than the image linked to your reference to Time's Photos of the Week yesterday, which is the purest kitsch—an iconic composition lifted from abstract expressionism (Adolph Gottlieb, maybe?) that erases everything about its subjects except that they are grunts and employs the sun as shorthand for both punishment and glory. It is an up-to-the-minute, brand-identity kind of military propaganda. It is vile. I know you didn't choose that particular image, but your examples make me wonder what you mean by "art." Heroic couplets? Ever read Martha Gellhorn's war reportage, for example, or Michael Herr's? You can read the AP wire to get the outline of what happened, but if you want to go any deeper you have to go to artists. Art has nothing to do with taste, and everything to do with depth.
But maybe you don't want depth. You seem to be indicating that the sorts of images you prize are the cathartic ones—the talismans—that avoid doubt and complication and go straight for the emotional jugular. You want pictures that will work on their viewers in the service of justice and peace—no argument from me there, except that I'm dubious about how often such pictures ever change anyone's way of thinking. On the one hand, I do believe that in a war it is necessary to broadcast images of the other side's civilian casualties, to disabuse the naive and undercut triumphalist rhetoric. On the other hand, I know all too well that people who have convinced themselves of the nobility of their nation's or faction's cause will simply not see evidence to the contrary. They will look past it, or if it is sufficiently strong they will deny its credibility. And while this doesn't mean that images cannot influence opinion, a single image that can do such a thing is rare, and cannot be counted on, and black magic won't make it happen, and favoring blunt-instrument images because there is a remote chance they might sway opinion is a sure way to immunize everybody against their power—since in the meantime you will have accumulated a lot of image-bites that everyone will tune out. Photography, like any art worth its salt, is in the business of telling the truth, a truth that is usually complicated and awkward. Human laziness and fatigue and the culture that merchandizing has made ceaselessly conspire to simplify the truth—which is inevitably to betray it. Pain, of course, is pretty simple, but its causes seldom are, and photographs have a greater responsibility than just to assert that pain exists.
Thanks, Jim, this has made me think, and you've been an awfully good sport.