The video of US marines urinating on Afghan corpses does not shock me. Though their behavior is disgusting and unacceptable, I find the public's reaction to this video far more troubling. People are not outraged that there are dead Afghans; they are outraged at the manner in which the dead are treated. This is indicative of our culture's tolerance for war and war crimes – as long as they are done in a gentlemanly fashion.

During the second siege of Fallujah, blatant war crimes were committed, yet the corporate media reported them with indifference. The siege itself was a war crime, according to the International Committee of the Red Cross Summary of International Law, because indiscriminate tactics were used, constant care was not taken to protect the civilian population, proper distinction between civilians and combatants was not made, medical personnel and medical units were not protected, indiscriminate weapons were used, and recent research about the current health crisis in Fallujah suggests that poisonous weapons may have been used as well.

Many of these war crimes were reported by the corporate media, though they were not described as such. For example, the New York Times reported on 8 November 2004 that American forces "seized" the Fallujah general hospital. An incident that I witnessed, as did Paul Wood and Robbie Wright from the BBC, was when my unit fired grenades into a house until it collapsed – with full knowledge that there were two resistance fighters and a young boy (roughly 10 years old) inside. Paul Wood interviewed the lieutenant at the scene, and he acknowledged that they had killed the young boy. In both of these reports, war crimes and Geneva Conventions were never mentioned, and the façade of honorable conduct was preserved.

What did not make it into the news was my behavior in Fallujah and the behavior of others in my unit, which I am certain would have elicited outrage equal to that elicited by this video of the urinating marines. I believe that the second siege of Fallujah can correctly be characterised as an "atrocity-producing situation". Our false beliefs about who we were fighting, our dehumanisation of Fallujans, our desire to "see combat" (a cute euphemism) and to get a confirmed kill, and our longing for revenge for lost comrades against a faceless enemy all conspired to create a bloodthirsty and lawless atmosphere.

I witnessed marines stealing from the pockets of dead resistance fighters and looting houses. I've heard firsthand accounts of marines mutilating dead bodies, of a marine who murdered a civilian, and of a marine who slit a puppy's throat. As the days of the siege passed, we used increasingly indiscriminate and illegal tactics – like "reconnaissance by fire", which is when you fire into a house to see if anyone is inside. The violence, the hate and our distorted sense of morality made many of us sick, including myself. I stole a black ski mask out of someone's home, because I wanted to take it home as a trophy, as evidence that I had fought against the "terrorists".

My behavior and the behavior of others in my unit was despicable, as was the behavior of these marines urinating on corpses. But we shouldn't let ourselves be fooled that an immoral mission and immoral war could ever be conducted in an honorable manner. War crimes were implicit in the invasion and occupation of Iraq, and they are abundant in the continued occupation of Afghanistan.

Yet, many of us choose not to see these war crimes, even though they are right in front of our faces. Only when a shocking YouTube video comes along, do we choose to look. And even then, what we see is the urinating, not the dead bodies.