Overdue vindication for the security services It has taken four long years, but the investigation into allegations that officers working for MI5 and MI6 colluded in the torture of al-Qaeda suspects has finally concluded that there is no case to answer. The police were originally asked to investigate accusations made against MI5 officers by the former Guantanamo detainee Binyam Mohamed, a British resident originally from Ethiopia who claimed that he was tortured - with the knowledge of MI5 - after his arrest in Pakistan in 2002. This was expanded to include MI6, thanks to an incident involving a detainee at a US-run prison in Afghanistan. Following an exhaustive study of both cases, Keir Starmer QC, the Director of Public Prosecutions, has concluded that no charges should be brought. The announcement yesterday by Mr Starmer and Lynne Owens, assistant commissioner of the Metropolitan Police, will come as a great relief to the intelligence and security services. For the past four years, they have had to carry out their vital work in the most trying of circumstances, contending with a barrage of accusations from civil liberties activists more concerned with their own political agenda than the available facts - or the security of the nation. This sustained legal campaign against the intelligence services played into the jihadists" hands; it is very much to MI5 and MI6"s credit that, whatever the effect on morale, they did not allow it to distract them from their mission. The reason the investigation took so long, we are told, is that the police were determined to leave no stone unturned. That makes it all the more depressing that the matter does not end there. As one inquiry closed, Scotland Yard announced that it was starting another, into claims that Britain was involved in the "judicial rendition" of two Islamist militants to Libya. In addition, "wider allegations of ill-treatment" are to be examined by the Detainee Inquiry, chaired by Sir Peter Gibson. Where will it all end? Of course, in a civilised country we need a system to ensure that our intelligence services are accountable for their actions. At the same time, they need to be able to work effectively in what are challenging conditions. Not only have MI5 and MI6 had to divert significant amounts of manpower and resources into assisting with these investigations, but their officers have had to act in the knowledge that they may be the subject of spurious and deeply damaging allegations, which will result in their every action being picked over years later. The legal system must safeguard individual liberties - but it must also give the intelligence services the protection they need if they are to maintain this country's security.