Having secured the convictions this week of three homegrown terrorists who had plotted to blow transatlantic airliners out of the sky using bombs disguised as drinks, Britain's security service is enjoying its proudest antiterrorism moment in years.
The recent past has included its share of setbacks. Nine Pakistani students suspected of involvement in what Prime Minister Gordon Brown claimed was a "very big plot" were released without charge in April.
But Monday's high-profile convictions of three young British Muslims, following the largest counterterrorism investigation in British history, is being widely praised.
Abdulla Ahmed Ali, Tanvir Hussain, and Assad Sarwar were found guilty of conspiring to bomb several airliners on routes serving Britain, Canada, and the United States. Prosecutors said the men had planned to make explosive devices from the common disinfectant hydrogen peroxide, batteries, and other household goods while in flight.
Their arrests, and those of a number of others in August 2006, radically altered aviation security for millions of travelers by prompting restrictions on liquids.
Paul Cornish, professor of international security at the Chatham House think tank, said the convictions were evidence of a well-run investigation. "I would also suspect that a lot of work is actually still ongoing," he says, "and has yet to be revealed."
Months of intense surveillance of key suspects, which involved installing a hidden camera in a London apartment that was used as a bomb factory, were described today in The Times by Andy Hayman, a former senior London police officer involved in the operation: "At times like this the police service is at its best: no fuss — just fast, old-fashioned police work."
He also suggested that the police had to swoop in on the plotters sooner than they wanted to because a British-born man who was suspected of being the terror plan's mastermind was arrested in Pakistan due to US pressure.
"We thought we had managed to persuade them to hold back so we could develop new opportunities and get more evidence to present to the courts," Mr. Hayman said. "But I was never convinced that they were content with that position. In the end, I strongly suspect that they lost their nerve and had a hand in triggering the arrest in Pakistan."
Causes for concern
But while headlines today were generally congratulatory, some experts were quietly striking notes of caution.
Describing the case as a "mixed bag," Andrew Silke, director of terrorism studies at the University of East London, pointed out that four other men were found not guilty of involvement in the suicide-bomb plot.
"The general sense at the moment is that this was the last of the really big terrorist cases, at least for some time. There was a peak in the level of the threat around 2005 and 2006 but that has now declined," says Professor Silke, who cited the British drawdown from Iraq as a crucial factor in cooling passions among some young British Muslims who might otherwise have been attracted to militancy.
Separately, he points out that the intelligence-led operation was coincidentally being celebrated at a time when it appeared that the end may be dawning for a system of controversial "control orders" used against a small number of terror suspects who are electronically tagged and subjected to an almost partial house arrest rather than being charged and imprisoned.
A man regarded as one of Britain's most dangerous terror suspects was released last week from his control order so that the authorities could avoid disclosing secret evidence against him during a court appeal by his legal team.
"The evidence of the past, such as when internment without trial was used in Northern Ireland, is that this type of approach is counterproductive. For really dangerous people, you have to mount surveillance operations and gather the evidence you need for a prosecution," says Silke.
Margaret Gilmore, an analyst at the Royal United Services Institute think tank, said that there's no evidence that the convictions are having any impact on the radicalization of British Muslims.
"I'm not sure these latest convictions will have huge impact on reengaging disaffected young radical Muslims," she says. "Counterterrorist officers keep telling us this is a generational problem and will take a generations [several decades] to solve, and I think that's true. I don't see any sign that the number of young people being radicalized has fallen dramatically in the past couple of years.
"The UK security agencies were slow in establishing the extent to which people on the Afghan/Pakistan borders were pulling the strings in terrorist plots against the UK," she adds, "and have now shifted their focus more in that direction, which should mean they will be more aware of those being radicalized abroad when they come back into the UK. "