My brother went into the army at sixteen. He made corporal and opted out after many years' service - to joing the police and relocate his young family to Northampton. I visited him at his barracks near Hanover in Germany and in Colchester. As such, I am unable to maintain the kneejerk antipathy to the military that ever other fibre of my body is dying to have. I may disapprove to the very marrow of my bones of illegal wars and foreign adventures dressed up as "humanitarian intervention" or "regime change", but I can't just write off soldiers as willing, unquestioning servants of Queen and country, or tools of imperialism and state terror. Even though by definition they are. My brother found a career in the army that made not a man of him, as per the recruiting posters, but a citizen. As a policeman, now CID, he is forced to almost be a social worker to meet the constraints of the modern force, and is anything but a bigoted bully boy. I was uncomfortable when he did tours of Northern Ireland, as by then my worldview had started to take shape away from the shadow of my parents. For all the reflex protestations about there being "a bloodbath" if the British Army pulled out, I couldn't see past the image of colonial Britain, almost on my doorstep. Meanwhile, I was aware that my brother could get killed. I think what I'm driving at is a broader understanding of my reaction to The Mark Of Cain, Channel 4's apparently controversial drama by Tony Marchant about our boys in Iraq, three months after the invasion. Rachel Cooke in the New Statesmen really took against it, describing it as "anti-British propaganda", and "unfair" and "unjust". Was it?

She was quick to praise its star, Gerard Kearns (Ian in Shameless), who played one of two young soldiers court martialed for their part in the abuse of Iraqi civilians while in military custody in Basra. Matthew McNulty (above), whom I didn't recognise, played the other. These two put in exceptionally rounded performances, Kearns obsessively trying to scrub the desert sand out of his hair, McNulty blowing the gaff by showing his "holiday snaps" to his girlfriend, back home, who was horrified by what she saw. (We didn't see what actually happened when she did, just the reflected light of a laptop in her appalled eyes, but we could guess. The drama's only real weak point was in buckling under the pressure of the Big Reveal and showing us, graphically, what actually happened at the end, in flashback, as the military tribunal unfolded. This was unecessary. We got the picture, without seeing the picture.) With a large dose of A Few Good Men, this was not so much about Iraq, but about military justice. In-house, as it were. It all came down to regimental loyalty in the end: would Kearns and McNulty testify against their fellow soldiers, including their corporal, and point further up the chain of command, or take their punishment like men and keep to the mantra What Happens On Tour Stays On Tour?

If you didn't see it, or chose not to watch it because you've had your fill of real events in the Middle East, I recommend The Mark Of Cain, should it be repeated (which is why I won't talk about the ending). Certainly, the British Army didn't come out of it smelling of roses, from dozy officer to dimwitted grunt, but at least we saw what pressure they were under, at one stage advised by the Iraqi military police to "keep the peace" by taking a Kuwaiti petrol smuggler and beating him to a pulp, to avert a riot. The implication was: out here, the rules are different. It was the obliteration of a commanding officer and a Territorial in a mortar attack that ultimately led the men to their vicious treatment of seemingly innocent suspects, one hot night.

I haven't yet consulted my brother on the realism of this drama, and he never served in the desert, so it may be that he won't be able to say for sure, but my guess is that men lose it out there. Men who are told they are liberators and peacekeepers and are yet treated like the enemy. Men who spend an awful lot of time doing very little but sunbathing. Men who are fully aware that the war they are fighting was based on flimsy evidence. (We heard snippets of news stories about David Kelly.) Let's not be coy, the army attracts a certain type of person. It has to. I wouldn't last five seconds. It's about as far removed as any job I could ever imagine myself doing. Thus, it's hard to get inside the mind of a soldier. I think Tony Marchant did a half decent job. It's the polar opposite of those Army recruitment ads, and in many ways better than Jarhead, the recent Gulf-set Hollywood movie whose message seemed to be: these guys are simply bored. They have to let off steam.

Interesting that The Mark Of Cain was pulled from C4's schedules during negotitations with Iran to get the hostages released. What did they think might happen?