British Try to Balance Risks in Terror Probes

British antiterrorism sleuths call it risk management.

It’s not jargon from the corporate boardroom, but rather a nerve-racking form of psychological combat based on knowing when to pull your punches and when to deliver the knockout blow: If you move too soon, the case might fall apart. If you’re too late, you might end up counting corpses.

Cultivated for years by European security forces, this patient approach was the driving philosophy behind the extended surveillance operation that culminated last week in the arrests of about 40 people in Britain and Pakistan suspected of plotting to blow up U.S.-bound planes over the Atlantic.

The investigation began almost a year ago. Aided partly by a tip from the Muslim community, British police and MI5 intelligence agents initiated surveillance of two seemingly distinct extremist groups, British officials say. The suspects were a mix of British Pakistanis and converts spread among three communities in the London area as well as the city of Birmingham.

Investigators discovered that members of one group had trained at a militant camp in Pakistan, a British law enforcement official said. And soon the surveillance showed that the two groups were connected and that police were watching a potential terrorist cell take shape, the law enforcement official said. Scotland Yard’s anti-terrorist division launched an investigation fusing the two inquiries.

The police anti-terrorism chiefs oversaw the investigative team, building evidence for prosecution, while MI5 and Special Branch police intelligence officers continued the surveillance, their specialty. The British system works well because it integrates intelligence and investigation in this way, a prerequisite for extended investigations, experts say.

Teams of dozens of officers -- at least six are needed to follow one suspect -- tailed the group, intercepted their phone calls and tracked their travels and financial transactions, British security officials said. Although the suspects communicated from Internet cafes to avoid detection, investigators were able to identify the computers they used, officials said.

Anti-terrorism chiefs increasingly became convinced that the alliance of the two cells planned mayhem on a massive scale: a multiple bombing attack on as many as nine U.S. planes using smuggled liquid explosives. But the investigators chose to wait.

“It has all the hallmarks of a classic long-term investigation,” said David Omand, who until last year served as Britain’s security and intelligence coordinator. “Following leads, developing information, finally getting eyeball contact. Then following them, bugging them, tracing leads through. Then the crucial decision on when to haul them in.”

Omand knows the harrowing terrain. During his tenure overseeing counter-terrorism operations, he had to contend with threats such as an Al Qaeda plot, devised by terrorist mastermind Khalid Shaikh Mohammed as a follow-up to the Sept. 11 attacks, to crash hijacked planes into British landmarks.

And Omand engaged in excruciating calculations in response to a tip from a strong intelligence source in February 2003: Terrorists armed with a surface-to-air missile were preparing to shoot down an El Al jet at Heathrow Airport, the source told British intelligence agents. After a frantic 24 hours of investigating and analyzing, Omand decided to deploy tanks and troops at the airport to dissuade an attack, which never came.

“They were all nail-biting options,” said Omand, now a professor at King’s College London. “Do you let it run covertly, stake the airport out? Do you close the airport and create chaos, which would achieve their aims? Or -- the only alternative left open to us -- do you make an enormous fuss to send them scuttling?

“The balance in this case is the same” he said, referring to the alleged airline bombing plot. “Can you let the operation run or must you do something to protect public safety?”

This year, as that plot developed, authorities were confident that their surveillance, assisted by Pakistani security forces, was meticulous and that an attack was not imminent. History shows that British police are adept at infiltrating and manipulating suspected plots in progress to reduce the dangers.

In an alleged plot broken up in 2004, half a dozen men now on trial here allegedly trained in Pakistan, made contact with Al Qaeda figures and stockpiled half a ton of explosives in a storage locker for a truck-bomb attack on a London shopping mall or nightclub.

The police took many precautions: They deployed a female undercover officer as a receptionist at the self-storage facility west of London. Video footage played in court in June showed her greeting the suspected ringleader when he went to inspect the giant bag of ammonium nitrate. He didn’t know that police had already slipped into the locker and replaced the apparent bomb-making materials with a dummy bag, according to testimony.

“What it illustrates is that there are ways of reducing the risk to the public,” Omand said. “There have been similar operations mounted with detonators being switched and so on. People can suddenly decide to move, so you have to be prepared.”

Like the British, other European security forces have developed similar techniques that combine the use of well-placed informants with human and high-tech surveillance. The British honed their tradecraft during the campaign against the Irish Republican Army, the Spanish against Basque terrorists, the French in response to violence by various Middle Eastern networks.

Terrorists are rarely unknown assailants striking out of nowhere. Even when they failed to thwart attacks in recent years, European anti-terrorism agencies had in-depth previous knowledge of extremist cells that got past the defenses.

Most of the 40-odd suspects charged in the Madrid train bombings of 2004 had been monitored for months. Spanish police had cultivated an imam close to one group of suspects as an informant. The anti-drug unit of the paramilitary Guardia Civil intercepted phone calls among narcotics traffickers-turned-terrorists as they transported stolen dynamite that would be used in the attack. But because those agencies and the Spanish intelligence service did not communicate effectively with each other, they did not realize an attack was imminent.

Similarly, the Dutch intelligence service spent several years shadowing the extremist cell involved in the assassination of filmmaker Theo van Gogh in November 2004. Dutch agents even used informants to coax a key suspect into moving into an apartment that had been bugged, enabling 24-hour intercepts of his conversations. The authorities did not detect the assassination in the works, but the wiretaps helped them raid the apartment and capture suspects preparing follow-up attacks.

And although the transit system bombings in London last summer caught British security services off-guard, several of the bombers had appeared on the periphery of the investigation of the 2004 truck-bomb plot.

British authorities have been working to beef up intelligence-gathering on Islamic extremists, particularly in regions far from London where coverage of Muslim communities was weaker than in the capital, officials say. MI5 is expanding rapidly to achieve the goal, adopted after the Sept. 11 attacks, of doubling its size, Omand said.

The chiefs of the police anti-terrorist branch have final responsibility about when to abort surveillance and make arrests.

“MI5 usually starts and develops surveillance, but they would engage [the police] from the start and bring in Special Branch to augment surveillance,” the British law enforcement official said. “In the operational phase, the anti-terrorist branch develops the evidentiary package. And they make the call about what is the trigger for taking action.”

The trigger in this case came this month when Pakistani police arrested Rashid Rauf, a British Pakistani accused of being a central figure in the alleged plot. The reasons for the timing of the arrest are unclear. Pakistani officials were working closely with the British, who wanted to continue the surveillance, according to most accounts.

There have been reports that U.S. officials pushed for the arrest as they became concerned about a plot that allegedly targeted American planes and intended to match the carnage of the Sept. 11 attacks. One version suggests that the U.S. government pressured the Pakistanis into capturing Rauf, the British law enforcement official said.

“The Pakistanis had pretty airtight coverage,” the law enforcement official said. “The story is that the Americans told them to make the arrest because they wanted to take Rauf out of circulation.”

U.S., British and Pakistani officials have denied conflicts and said the case was a textbook example of international cooperation. That debate aside, experts agree that U.S. law enforcement, though experienced in complex investigations of organized crime, is less willing to sit tight when it comes to suspected terrorist plots.

“My experience with transatlantic relations is that the Americans are less inclined to risk management and want to go for safety first,” Omand said. “That’s not a criticism; it’s a question of a different law enforcement culture.

“And it is changing. Tom Ridge said once that the U.S. had to learn about risk management,” Omand said, referring to the former U.S. Homeland Security secretary.

Rauf’s capture in Pakistan set off a chain reaction here. Fearing that the suspects would flee or speed up plans for the attack, British police swarmed on them. They are holding 23 people and have conducted more than 60 searches of homes, businesses, cars and a wooded area.

Searches and interrogations continue as anti-terrorism authorities advance the cumbersome process of building a case from a large amount of raw material.

“They are logging 1,000 items a day,” the law enforcement official said. “The intelligence operation around this was months in the making.... Going into the searches, they knew exactly where to look and what to look for.”