Why are the British and US governments saying the leak of military documents about Afghanistan has "put our soldiers at risk?" It's us who's been kept hidden from this information, not the Taliban. For example, many of the revelations are previously hidden details of civilian casualties, but Afghans in those areas probably already knew about those deaths. I don't suppose local insurgents have said "Well well, I've read the leaked documents, and you know that family whose house was bombed to rubble by an American plane, and the rest of the village arrived and wailed for three days and swore revenge and then there was a funeral that we all went to. Well it turns out they're dead."

One typical story in the documents tells how in March 2007, following an explosion, marines opened fire with automatic weapons as they drove down a six-mile stretch of road, killing 19 civilians including teenage girls in fields, motorists and an old man. But when they made a military report on the episode, they wrote that after the explosion the "patrol returned to base". This was accurate, as far as it went. It just missed out the details in between. But I suppose with all the excitement of returning to base you can easily forget the other bit of the afternoon, where you shot up half the neighbourhood. In any case those forms are so complicated, who wouldn't miss out on all that box-ticking after a tiring day.

Other documents reveal details of attempts to win over the locals. So one says: "The village of Mamadi is definitely anti-coalition. They want nothing to do with us." There are similar accounts, but then an endearingly optimistic report about a visit to a school in Nuristan, that says: "They were very friendly and wanted to talk to us. Some of them threw rocks at the soldiers, but it all appeared to be in good fun." So it seems the soldiers experienced the traditional friendly Nuristan greeting of rock-hurling. Because as anyone knows, the time to worry in Nuristan is when you say hello and they don't sling a rock at you, then you know you've offended them. But when they see you coming and immediately roll a boulder at your head you're practically family.

Another objection to the leaks is even more unlikely, that the information is irrelevant because it concerns events of a few years ago, before these problems were sorted out. Indeed, some of these accounts of civilian casualties took place way back in the olden days of 2008, when the war was in its infancy, barely seven-years-old. And as any military expert knows there are always teething troubles in any war for the first seven years, until year eight when matters suddenly sort themselves out and get settled.

So the main attack has been the traditional one with a leak, to ignore the lies, disasters and deaths revealed, and instead become furious at whoever exposed it all. If you report a murder to the police, you wouldn't expect to turn on the news later and hear: "The police have said they'll do all they can to catch the sick individual who revealed there had been a murder."

If things were going well they probably wouldn't mind leaks detailing levels of corruption. Unless they said: "Oo, it had all come together so well it looks like we'll be finished by September, with democracy and all the warlords doing community service, and we were going to announce it as a nice surprise and now you've spoilt it, Wikileaks."

Instead the documents reveal the Taliban's weaponry is greater than admitted, and the Afghan army is riddled with corruption and victory seems unlikely, far from the official declarations that it's all going to plan.

Secrets are essential not because of the danger when information gets to insurgents, but because of the danger when information gets to us. For we might conclude that having an army in Afghanistan for no coherent reason appears to putting them and the Afghans at a certain amount of risk.