But the way in which it happened is even more damaging. The five British men and three Afghans were shot dead by an Afghan policeman. The Afghan National Police (ANP), together with the Afghan National Army (ANA), are the exit strategy. The way out. The people NATO hand security over to.
The last thing NATO strategy needs at this delicate moment of reassessment is a broad wave of distrust sweeping NATO troops towards their Afghan counterparts.
This is, as far as the British army will say for now, what happened: at 15.15 hrs yesterday British troops and Afghan police were in a debrief after a foot patrol. They live together in a compound near a checkpoint in Shin Kalay, that’s 400 metres from the British base in Nad-e-Ali (incidentally another compound where they live alongside the ANA).
Fourteen British soldiers protect 2 British police mentors, who teach 15 Afghan police. There were no barriers, we understand, between the Brits and Afghans – they lived side by side, part of the NATO bid to win the trust of the Afghan men they fight alongside, and hope to leave the fighting to.
The UK military have a photo of him, and know his name. Local sources say, unsurprisingly, he’s now joined the Taliban, with his AK47.
There will be questions as to how he managed – savagely – to kill 8 armed men and wound 6 other Britons without, it seems, being shot dead himself. That’s for the investigation to work out.
But another question remains, a more serious one: what will this do to the confidence of British troops working in that area? And the relations between the part of Afghan society NATO needs most – its troops and soldiers?
Will the Taliban claim this attack as one of their own and claim they’ve infiltrated the police? Or will this rogue policeman be caught and both sides hope it will never happen again?