The news reports from Iraq in the last few weeks have proven once again that, when it comes to weapons of war, nothing packs as much firepower as a camera. The shock and awe of some crude snapshots taken by amateurs may well be more devastating than all the cruise missiles in the U.S. arsenal.

Why images are in many cases so much more potent than words is a metaphysical puzzle that art theorists have never quite resolved. But even the Secretary of Defense, apparently too busy to read a 53-page report detailing the horrors at Abu Ghraib and tell the president about them, should have smelled trouble for the American cause in the Middle East when he learned that the photographs existed. That he didn't act more forcefully to bring the scandal to light may mean that he didn't regard these practices as out of the ordinary; or, he may have understood that photographs of the abuses would overwhelm any explanation that Central Command might have come up with.

The illusory immediacy of the medium no doubt accounts for some of its power. The event depicted may have taken place minutes or years ago; and yet each time we look at a photographic image it's as though we are actually there at the moment the shutter was clicked. By capturing the light of the past and embedding it into the chemical fabric of its own production, photographs offer convincing, “scientific proof” that something happened or once existed. Unless we actually see a picture of a female reservist holding a naked Iraqi man on a leash, most of us would have difficulty believing that it had taken place, and those in charge would have a far easier time denying it.

What must drive the Pentagon crazy about the Abu Ghraib scandal is that after working so successfully to keep accredited photojournalists away from the front lines during the Gulf War and the Iraq War -- in case someone should witness and record another My Lai or just an ordinary, lopsided, guts-spewing firefight -- it turns out that the most damning evidence against American troops was produced by the troops themselves. Indeed, it was hard to tell from Rumsfeld's testimony on Friday which upset him most: that acts of brutality had occurred; that photographs of such acts existed; or that someone had released the evidence to the press.

Censorship can give an energy boost to any image. Whether stating self-evident truths we had been prevented from seeing (the coffins bound for Dover Air Base) or confirming rumors we hoped might not be true (the abuse of Iraqis prisoners), photographs exert maximum impact when they blow the locked doors off the forbidden. Most of us have plenty to hide -- especially governments in wartime -- and cameras are sneakily effective at disclosing ugly realities and inflaming passions beyond reason.

Yet, the meaning of any photograph is unstable and dependent on social context -- another quality of the medium that makes authorities nervous. Words are often not only far more precise than images, they are necessary for their interpretation. Roughly 50 percent of the families related to the U.S. military personnel inside the coffins felt that publishing the pictures was a dishonor to the dead and a violation of their privacy; the other half regarded dissemination as long overdue public recognition of the sacrifice felt by those involved.

The photographs of naked, faceless Iraqis in Abu Ghraib, stacked like firewood and forced to masturbate for their captors, are far less ambiguous. Male nudity may have a specific and heightened Middle Eastern meaning, but Muslim and non-Muslims alike recognize cruelty when they see it.

As with many acts of violence, perhaps the creepiest revelation is the absence of shame by the perpetrators. They do nothing to hide their actions from the camera; rather, its presence may have abetted and validated the degradation. The gleeful Iraqi men and boys who stoned and tore apart the dead bodies of the American contractors in Fallujah were performing in the street for their photographers. Similarly, the Animal House antics of the men (and, a novelty in the annals of American torture, women) at Abu Ghraib seems intensified because they know someone is watching and recording them. (The cellblock's party-hearty atmosphere, so visible in many of the photographs, however, may end up as the soldiers' best defense should they argue that abuse of prisoners was officially sanctioned from on high. It's not as if these scenes were taking place in darkened closets or secret chambers.)

The mindless simplicity of the photographic image has always been a source of its strength. Most cameras require no expertise to operate well. A person only has to be standing in the wrong place at the wrong time and press a button to precipitate an earthquake, as George Holliday found out in 1991 when he happened to witness the L.A. police clubbing a black man on the side of the road. Abraham Zapruder produced the most valuable visual document in American history by accident. With the technology for creating photographic images advanced to the point where strangers can take snapshots of one another with cell phones, we must now assume that everyone we meet is armed and ready to take our pictures.

The story of Abu Ghraib won't be fading anytime soon because it will be driven by images, the fuel of television. Rumsfeld promised on Friday that more and worse photographs are yet to come. Seymour Hersh's latest dispatch in The New Yorker claims that a video exists of guards raping Iraqi boys. If the videos have recorded sound, it's a good bet that a few phrases will become sick, ironic catchphrases with comedians and the chattering classes. So far those in the photographs have been singled out for most of the press attention. U.S. Army Pfc. Lynndie England, the 21-year old from Ft. Ashby, West Virginia, has been featured in numerous stories. Depending on one's sympathies, she is either the symbol of conscienceless American oppression, pointing to a prisoner's genitals while beaming for the camera, or a patsy who was acting at the suggestion of her boyfriend and who is being set up for punishment by her invisible superiors.

In the next few days and weeks we should learn more about the people behind the cameras. It is against the Geneva Convention to photograph prisoners in order to humiliate them. According to The Washington Post, Sabrina D. Harman, a 26-year-old Army reservist from Alexandria, Virginia, is accused of directing many of the shots that have been released.

She allegedly both created and photographed the pyramid of naked prisoners, ordering them to strip and masturbate in front of others. She also supposedly photographed a corpse and then posed with the body while someone else took their portrait. Finally, she is charged with writing "rapeist" on a prisoner's leg and with staging the most haunting photograph so far published: the cloaked prisoner who stands on a box with arms outstretched and wires attached to his hands. Like an apparition from The Blair Witch Project or The Passion of the Christ, he is both a figure of horror and of pity. Harman apparently threatened the prisoner that if he fell off his tiny perch, he would be electrocuted.

When weighing the guilt in the court-martial cases during the next few months, the prosecutors and the public will have to decide who should be held more responsible: the torturer of the prisoner or the photographer of the deed. Although both may be culpable -- and in some cases they are one and the same -- the photographer can argue that he or she was attempting to document the abuse. Indeed, there seem to be various sensibilities present in the photographs. An overhead wide-angle shot published in Friday's Washington Post had the quality of a documentary surveillance photo, as though the person pressing the shutter were exposing and not celebrating a crime. No doubt this defense will be presented when the photographers at Abu Ghraib are brought up on charges.

Who leaked these pictures to 60 Minutes II and The New Yorker, and why, is another aspect of this story that deserves closer scrutiny. Were all of them collected during Maj. Gen. Antonio Taguba's investigation? Or have some of them been filtered out to the press by lawyers hoping to portray their clients as crusading photojouralists?

The media sifts through the thousands of images that are produced every day and, together as a culture, we decide which of these are most meaningful, compressing a few through repetition into icons. It is telling that during the first year of the war the most memorable images were the toppling of Saddam's statue and the close-up of the dictator himself being check for head lice. Now, as the war seems to have gone terribly wrong,
the icons are the charred slabs of flesh hanging from a bridge in Fallujah and the Christ-like scarecrow of Abu Ghraib.

It may be specious to connect the dots between the wars in Vietnam and Somalia and Iraq, attempting to draw history lessons. They differ from one another as much as they resemble one another. But the three have now produced at least one thing in common: a group of mind-searing images whose repercussions no one can control or predict.

Richard B. Woodward is an arts critic in New York City.