Let them read the documents. Let them try to tell us after that (as some still do, even now) that the Afghan war was fought well, and fought morally; that Guantnamo was a limited and necessary evil; that there was nothing that amounted to torture; that the prisoners stolen from across the world were almost all fanatics; and that it was necessary for democratic states to excuse themselves from the rule of law in order to save it. If you could only know what we can know, you would understand that what we are doing is right, our leaders used to assure us. Well now we really do know we have the documents, we have the transcripts of interviews with former prisoners, we have everything it takes to understand the nasty story of Guantnamo, exposed today in 759 leaked documents containing the words of the people who ran the place. And it is obvious that we should have seen through the evasions from the start. The leaked files published by the Guardian and the New York Times reveal horror that lies only partly in the physical things that were done to inmates the desperate brutality of heated isolation cells, restraining straps and forced interrogation. Such things are already grimly familiar and have been widely condemned, and perhaps for the 172 inmates who remain in Camp Delta despite President Obamas promise to close it, they continue in some lesser form. Worse things have been done in war, not least by us British, as emerging evidence from the campaign against the Mau Mau in Kenya should remind us. But what is given new prominence by these latest Guantnamo files is the cold, incompetent stupidity of the system: a system that tangled up the old and the young, the sick and the innocent. A system in which to say you were not a terrorist might be taken as evidence of your cunning. A system designed less to hand out justice than to process and supply information from inmates, as if they were not humans but items of digital data in some demented storage machine programmed always to reject the answer No, I was not involved. The clinical idiocy of this dreadful place is the most chilling thing of all, since it strips away even the cynical but persuasive defence: it was harsh but it worked and it kept the world safe. It didnt work, much of the time. These files show that some of the information collected was garbage and that many of those held knew nothing that could be of use to the people demanding answers from them. Far from securing the fight against terror, the people running the camp faced an absurdist battle to educate a 14-year-old peasant boy kidnapped by an Afghan tribe and treat the dementia, depression and osteoarthritis of an 89-year-old man caught up in a raid on his sons house. Other cases are just as pathetic. Jamal al-Harith, born Ronald Fiddler in Manchester in 1966, was imprisoned by the Taliban as a possible spy, after being found wandering through Afghanistan as a Muslim convert. In a movement of Kafkaesque horror the Americans held him in Camp X-Ray simply because he had been a prisoner of its enemy. He was expected to have knowledge of Taliban treatment of prisoners and interrogation tactics, the files record. Again and again, what stands out from these stories is not some as yet undiscovered horror from the secretive steel-barred and orange-suited compound, but the chaos, the confusion and the casualness of it all. The people who ran this place were not deceived. They too could see that this was not the distillation of evil that the American government claimed it to be, but a shambolic catch from a trawl whose nets had dragged in all sorts of people, many of them by mistake. Some of the small fry and the innocent were eventually returned (it is important to acknowledge this) but innocence did not exempt them from ill-treatment, or a system of interrogation guided by a note among the files GTMO Matrix of Threat Indicators for Enemy Combatants that reads as if engineered to prove that people are hiding from the truth. It is no surprise that the files record that one in seven of those detained developed psychiatric illnesses. This was a place that portrayed itself as the ultimate expression of a forensic and rational war run by the most sophisticated power on the planet, with the best intelligence available. The reality was an almost random collection of the bad, the accidental and the irrelevant. The American state can be understood as such, but could never own up. Among the prisoners are very dangerous men: real terrorists, driven by hate and out to destroy the sort of liberal values we believe superior. Some of them had done things that merited imprisonment (although that does not mean it was necessarily Americas duty to seize them). Some are still there. But nine years after that creaking warrior Dick Cheney called the inmates the worst of a very bad lot, the possibility of prosecution has been polluted by his Guantnamo regime. As a result Barack Obama who was surely serious when he said that he wanted to shut the place has failed to make much progress in closing Guantnamo down. The Washington Post recently described the final sad failure of the presidents attempt to have Khalid Sheikh Mohammed, the alleged 9/11 mastermind, prosecuted in a federal court; he will now face a military tribunal of the sort the president once wanted to abolish. The half-life of the toxic slurry left by Obamas predecessors has made decommissioning the extrajudicial system too difficult. As the documents show, the camp has been left holding a miserable mix of detainees who have nowhere safe to go such as Yemenis and Chinese Uighur Muslims the demonstrably dangerous and the unprosecutable. Pull it to bits, and some of those still inside will try to hit back at the west (as perhaps 150 of those already released may already be doing). But keep it going, and this president is dragged back towards the his predecessors disaster. The final indictment of Guantnamo is not just that it broke the rule of law temporarily, but that by doing so it made the breach permanent. Justified as a way of gathering information from the guilty, it forced the innocent to invent falsehoods as well. The security forces and politicians who permitted the camp often accuse its critics of being simplistic and squeamish. They say that the things that happened inside it were much less nasty than the things the people it contains did to others. In some cases thats right. But the Guantnamo system piled lie upon lie through the momentum of its own existence, until no one could know which those cases were, or what was true. At times, I have feared that obsessing over the injustices of Guantnamo Bay has become a surrogate for a wider hatred of America. Read the files, and youll realise that obsession is the only possible humane response. Guardian