I first heard about the Syrian rebel who was supposed to have eaten a heart on Monday, when a friend who lives in Beirut tweeted something cryptic about abuse videos. Against my better instincts, I opened one of the links he attached to his tweet. It showed soldiers (or was it militia members? Rebels? It can be hard to tell in Syria) beating prisoners, whipping them with ropes. In the YouTube sidebar, there were a host of other videos, some tagged in Arabic and others in English, broadcasting their sickening contents: “18+, Basher Assad Soldiers Mutilating,” and so forth. After the warnings about graphic content, whatever video there is simply rolls, and whoever has chosen to click on it, whether over or under eighteen, watches it, and then lives with what he or she has seen.

Such videos have increasingly come to represent a new weapon in modern wars-by-terror. The phenomenon is not unique to Syria. One recent, much-commented-on video depicts the decapitation-by-chainsaw of a Mexican gang member by rival narcos. Violent networks around the world seem to have taken inspiration from Al Qaeda in their efforts to terrorize captive societies by filming, and broadcasting, the executions of their enemies. This began, to my knowledge, when Al Qaeda filmed Daniel Pearl’s decapitation, in 2002, and was followed, during the Iraq War, with a raft of real-life snuff videos courtesy of Al Qaeda and its allies: Margaret Hassan, a kidnapped British relief worker; the young American Nicholas Berg; many who got less attention because they were not Westerners. How many have we heard described in news reports since then? Usually, our television channels and newspapers have shown discretion, and what we have seen is, at most, merely a screenshot of the hostage looking abjectly into the camera—but we all know what came next. Most of us, I suppose, never think of actually looking up the video that shows the deaths themselves, because that would be prurient, brutal, and yet we all know they are out there. And, no doubt, there are plenty of people who do look for them.

It’s sobering to acknowledge that, for a previous generation of television viewers—not so long ago—the most terrifying thing they had ever seen (and for many it induced enduring fears) was the shower scene in “Psycho.” That’s so much “Captain Kangaroo” compared to what we can watch today, and if there were ever any question that what one sees on a screen has before-and-after consequences, consider these videos from the world’s killing grounds. If you want to see what someone looks like as he is stabbed, as he is told he is about to die, as he is beaten to death, or cut into pieces, it is all just a click away.

Once, some years ago in Iraq, where I was spending long periods of time reporting, I decided I had to look at one of these videos. Kidnapping and decapitation in front of a video camera was the nightmare fate that potentially awaited all of us there, and, on a Web site that offered a couple of dozen, I chose one at random to watch. It depicted the decapitation of a middle-aged Turkish trucker whose crime had been to carry cargo between Turkey and Baghdad, which was then under American military control. According to Al Qaeda’s extreme interpretation of what made an enemy, his was a crime that merited death, for the goods he ferried to Baghdad meant that the American troops, or the puppet government they defended, would be equipped with toilet paper, or mineral water, or gasoline.

The video began with the hapless Turk seated facing the camera, expressionlessly kneeling in front of men who wielded guns and swords and wore black executioner’s masks. Then one of them invoked God and began to saw unceremoniously at the trucker’s neck. Because of the poor bandwidth in Baghdad, the video continually cut out and began rebuffering, and so I watched the moment at which the Turkish trucker began to die several times, before I gave up and stopped. And so I didn’t see it through to what is the disturbingly intentional element of spectacle in all of these videos—the money shot—the moment after the head is freed from the body and the executioner takes it in his hands.

These latest Syrian videos—most of them, thankfully—end before the moment of death, but, as I trawled through several, there were similar scenes, of men objectifying others, whipping and beating them, tormenting them before what appeared to be their inevitable deaths. Any individual scene may be impossible to verify. In every single case, I felt soiled by the act of watching.

It was during this perusal that I ran across what has now been widely referred to as the rebel-eats-heart video, which Human Rights Watch has singled out for condemnation. As we now know, because the man who appears in it, Khalid al-Hamad, granted a Skype interview to Time, and the magazine had a surgeon watch the video, the organ in question was actually a piece of the victim’s lung, which al-Hamad thought was his liver, and not his heart at all.

What to say about this latest outrage? Al-Hamad is, clearly, a man in the full grip of the Syrian war’s killing fever, with all that that entails. To justify himself, he said he’d found a trophy video in his victim’s cell phone that showed the rape, with a stick, of a woman and her two daughters. In the kind of no-holds-barred war of hatred that is occurring in Syria, the killing is often close-up, and, in the desire to outdo the latest outrage committed by the enemy, the instincts that are unleashed can be akin, apparently, to those that are merely ritualized in the hardest of hardcore sado-porn. In the battlefield, there is nothing to hold the instincts back, and ultimately they merge there with the desire to commit to murder.

It has always been thus, and let’s not anyone forget it. The photographs from the Rape of Nanking, in 1937, are almost unbearable. In Vietnam, American soldiers collected Viet Cong ears, raped and murdered Vietnamese girls, and did so much more that we have long since forgotten about. In Afghanistan three years ago, several American soldiers were arrested after they were discovered to be “sport-killing” Afghan civilians, cutting off parts of their bodies, and posing for cell-phone pictures. (And we shouldn’t forget the Abu Ghraib snapshots.) Last year, in Afghanistan, another video emerged showing American soldiers urinating on the corpses of Taliban suspects. And so on.

In war, you kill a man, and, to take away the fear that you feel, you objectify him, you humiliate him, before or after his death; you exult in his death; you persuade yourself you have truly conquered him. This ritual is as old as mankind, and it is something we unlock every time we go to war, or cheerlead others into fighting a war for us. Maybe ninety-nine out of a hundred soldiers, or some even greater number, will limit themselves to doing what they have to do, and kill because they must, because their society asks them to, telling them that it is us and them, or because everyone around them is doing it, too, and because of the belief that if they don’t, they will be killed. But some number will also feel the need to desecrate the corpse, will pose for photos with it, will cut off an extremity, or eat a part of that body in an attempt to vanquish not just the flesh of the dead victim but his spirit, too—and, perhaps, destroy their own.

Illustration by Laurent Cilluffo.