Preventable errors

The attacks on London of July 7 2005 triggered a searching debate about the ability of the police and MI5 to cope with the threat of terrorism. Some people said that we needed further curbs on civil liberties; some pointed the finger at British Muslims and demanded more cooperation from them. But it is the competence of the security services that is now in question after revelations from the trial that ended yesterday at the Old Bailey with five men found guilty of plotting to cause mass murder in Britain using fertiliser-based explosives. Some of those convicted yesterday were seen by MI5 meeting two of the July 7 bombers.

Evidence from the case revealed that MI5 could, and perhaps should, have been alerted to a series of clues - 17 months before London was bombed - that Mohammed Siddique Khan was a dangerous and committed terrorist.

There were clues that, with hindsight, would have led to Khan, who led the July 7 attack, being identified as a threat. He was not, and the evidence of the errors points to a haunting conclusion: the bombings could have been prevented. It is the most serious missed opportunity we are aware of that counter-terrorism officials have been responsible for since the war on terror began. But there have been other mistakes in operations and in strategy.

Before the bombings, the security services had made several false assumptions. They assumed that the threat was primarily from north African jihadists, loosely inspired by al-Qaida ideology, and they discounted the prospect of British-born suicide bombers. In fact, the attacks were carried out by people who had grown up here, and who had been recruited, trained and directed by al-Qaida.

Counter-terrorism is one of the most important areas of government activity, yet it is one of the least scrutinised - and the latest revelations suggest that what scrutiny there is does not work.

The MPs on the intelligence and security committee that reported last year gave the security forces a largely clean bill of health. They even appear to have bought MI5's claim that it had never identified Khan before he took part in the attack on London. This claim now seems at the edge of credibility given that, in February 2004, MI5 operatives followed him from the south-east to Yorkshire and his home address as part of Operation Crevice, the codename for the investigation into the fertiliser plot.

Traditional British secrecy means that counter-terrorism officials face no meaningful public questioning, although senior US intelligence officials testify in the open, and their confirmation hearings are public. There is little in any area of life that cannot improved by accountability.

Greater scrutiny is possible without compromising national security. Since London was attacked sceptical voices in counter-terrorism have expressed doubts about the strategic direction taken by both their own chiefs and in government. Some officials believe a public inquiry is the only way to increase the effectiveness of the counter-terrorism effort.

If the case that ended yesterday leads to questions about the competence of counter-terrorism officials, then any failure to reduce the danger that al-Qaida poses should also raise questions about the government's strategy, and about why people want to attack Britain and murder civilians - and the role the government's foreign policy plays in their motivation.

The government's reaction to the errors revealed yesterday does not exactly inspire confidence that there is a system in place to detect slip-ups in intelligence and to fix them. The shadow home secretary, David Davis, summed it up yesterday: "Some mistakes are inevitable, and some are not."

Vikram Dodd