Photographs may be more memorable than moving images, because they are a neat slice of time, not a flow. Television is a stream of underselected images, each of which cancels its predecessor. Each still photograph is a privileged moment, turned into a slim object that one can keep and look at again. Photographs like the one that made the front page of most newspapers in the world in 1972—a naked South Vietnamese child just sprayed by American napalm, running down a highway toward the camera, her arms open, screaming with pain—probably did more to increase the public revulsion against the war than a hundred hours of televised barbarities.One would like to imagine that the American public would not have been so unanimous in its acquiescence to the Korean War if it had been confronted with photographic evidence of the devastation of Korea, an ecocide and genocide in some respects even more thorough than those inflicted on Vietnam a decade later. But the supposition is trivial. The public did not see such photographs because there was, ideologically, no space for them. No one brought back photographs of daily life in Pyongyang, to show that the enemy had a human face, as Felix Greene and Marc Riboud brought back photographs of Hanoi. Americans did have access to photographs of the suffering of the Vietnamese (many of which came from military sources and were taken with quite a different use in mind) because journalists felt backed in their efforts to obtain those photographs, the event having been defined by a significant number of people as a savage colonialist war. The Korean War was understood differently—as part of the just struggle of the Free World against the Soviet Union and China—and, given that characterization, photographs of the cruelty of unlimited American firepower would have been irrelevant.Though an event has come to mean, precisely, something worth photographing, it is still ideology (in the broadest sense) that determines what constitutes an event. There can be no evidence, photographic or otherwise, of an event until the event itself has been named and characterized. And it is never photographic evidence which can construct—more properly, identify—events; the contribution of photography always follows the naming of the event. What determines the possibility of being affected morally by photographs is the existence of a relevant political consciousness.