Ducky, I am not accusing you personally of anything. I said that the pessimism can easily be a blind for certain attitudes, not that it MUST be. Please read what I wrote, not what you THINK I wrote. With that said, I believe complete pessimism is misplaced, and is actually dangerous attitude (see below).
I admitted that it's a statement of belief on my part that photography CAN BE a positive influence, but it's a belief that has some supporting evidence. The fact is that photography's "influence" on warfare or human violence/oppression must be looked at on a case by case basis, of course.
In the case of Japan's colonial adventures (1905-1945), (state-sponsored as well as some popular/social and news) photography played a role in helping whip up a fervor for war and bloodshed. In the case of Vietnam, I believe that war journalism (including photography) played a role in turning US public opinion against the war, which arguably could / would have continued on much longer without graphic visual documents of what was happening there. There is no one-size fits all conclusion.
Your post seems to imply that unless photographs somehow make war obsolete or end it entirely that it's useless. That is, in my opinion, an unrealistic expectation -- Vietnam is a good example here: photographic evidence didn't prevent it or even immediately stop it, but I believe it helped end it sooner than it would have. The same is true for something like child labor. (Lewis Hine, anyone?) In cases like this, photography feeds into (i.e., contributes to, reinforces) wider social attitudes and developments, but that doesn't mean it's irrelevant.
The fact is that, as far as war (and other forms of oppression and violence) is concerned, other forces (psychological, political, technological, social, etc.) have exercised a far more decisive influence in making modern history drastically more violent and deadly than the pre-photographic era. But, the fact that photography hasn't ended human oppression doesn't mean it hasn't had some positive effects in particular cases.
Democracy hasn't ended war or poverty either, but do we just throw our hands up and say it's worthless?
The fact that I cannot empirically demonstrate that photography has decisively reduced human violence does not, for me, invalidate it: I cannot "prove" that art or political satire has a beneficial effect either, but in both cases I think that they are essential to a functioning democracy.
The real question is does the fact that we cannot say unequivocally either way mean we should avoid documenting wars? Does it negate or invalidate the ethical urge to protest at the mistreatment of fellow human beings? You seem to imply that because war is still prevalent and more violent than ever that we can just abandon the whole enterprise of documenting it. Do I assume you at least level the same skepticism toward photographs of racism, poverty, child labor, natural disasters, etc. and that you only "consume" and support "decorative" photos (sunsets, flowers, nudes, etc., -- things that make you feel good)? After all, the world still has racism, poverty, child labor too. And -- given the world's explosive population growth -- more people in absolute terms probably suffer from all of them than in the pre-photographic (pre-1850) world. Do we just stop reading about or viewing photographs of those things?
To be clear, I am not saying there are no ethical issues with conflict photography. There clearly are -- imbrication in business, media exploitation, etc. But to take the position that we can just ignore photographic evidence of war completely or even deny it as "truth" -- as I think you came close to doing when you said "can't see any truth being spoken" -- seems to imply that only "happy" photographs are "true" -- or that none are. A proposition I find absurd and (see below) pernicious.
I know that I have voted very consciously on the basis of a candidate's record of willingness to go to war and I have quite often discussed at length with other people (some of whom vote) my views on current wars and their atrocities. My views and voting habits are thus influenced by photographs from places like Afghanistan. I suspect that there are many people much like myself -- the fact that we cannot end war completely does not mean that there is NO positive contribution being made by documents such as Stanworth's. My experience, and others such as Vietnam, would suggest that your pessimism is somewhat overdone.
In short, I take the position that such photographs are a form of knowledge and that, even when it is hard to measure its effects, knowledge is a good thing. Pessimism and apathy about documenting the world as it is (good and bad) effectively help keep people in the dark, even if only by giving them a reasonable-sounding excuse to dismiss the information as "pointless" or "useless". Given that I am an educator, I take all attempts to cover up, dismiss, or simply ignore information to be a pernicious form of control and manipulation -- pessimism contributes to apathetic attitudes that make such control and manipulation even easier.
In answer to your question, "Do what?" I say, "KNOW! ... and then act on that knowledge as your conscience dictates." If it is talking to your friends, neighbors, colleagues, good. If it is joining or organizing a protest, good. If it's contributing money to veterans or orphans funds, or peace organizations, then good. If it is just voting for candidates you believe will help end (unnecessary) conflicts or oppressions, then good. I'm not going to dictate HOW you act, but I do fervently hope that you (and I) can follow our consciences in the context of having available to us the fullest amount of information possible. Photographs are -- to my mind -- a vital part of that information.
I suspect that there's no chance we're going to agree, so after that I'll bow out. My position is, doubtless clear: information is important and part of the preconditions for an engaged, politically responsible society ... photographs (even of conflict) are essential to that fund of information and thus are indispensable and to be valued, even if their contribution is "amorphous" (and even sometimes ambivalent).
EDIT: grammar changes. OOPS!
