KEY POINTS:
More than three years after Europe's deadliest Islamist militant bombings, the good news is that police and intelligence agencies have smashed a succession of cells bent on wreaking similar carnage.
The bad news is that the sheer volume of alleged plots - including in Britain, Denmark and Germany in just a few weeks this year - suggests they are battling to keep pace with a threat that has grown and shifted since the 2004 Madrid attacks, for which 21 people were convicted in Spain yesterday.
Nick Pratt, a former CIA official now at the George C Marshall European Centre for Security Studies in Germany, said: "We're seeing more of these [plots], they're more brazen. The planning has not slowed down - as a matter of fact I think it's increased, and Europe is the battleground."
The Madrid investigation revealed an operation that was low-tech but lethal. It cost just €54,000 to €105,000 ($101,000 to $202,000) to detonate 10 bombs hidden in sports bags and left on commuter trains.
The multiple train bombings in Madrid killed 191 and injured more than 1800 on March 11, 2004. The court found three men guilty of mass murder and attempted murder, and sentenced them to jail terms of between 34,000 and 43,000 years. Four others received lesser sentences. There were seven acquittals.
Plots since Spain have varied widely in their sophistication.
Pratt says the blueprints prepared by convicted al Qaeda operative Dhiren Barot for attacks in Britain and the United States were the work of "an absolute professional".
On the other hand, a failed car bombing in London and the ramming of a jeep filled with petrol canisters into a Glasgow airport terminal this northern summer were crude to the point of naivety.
The lack of a pattern - both in the modus operandi of attacks and in the profile of those who carry them out - is one of the factors that complicate the work of investigators.
At different times, the focus has shifted between foreign and 'homegrown' operatives, and between highly trained professionals and self-taught radicals who pick up their basic tradecraft on the internet.
Two of the four suicide bombers who killed 52 people in London in 2005 had trained in Pakistan, as had several men convicted in British trials this year, as well as all three suspects arrested in a German bomb plot in September.
Intelligence officials fear this trend may continue, given the success of what they call "core al Qaeda" in rebuilding its strength along the Pakistan-Afghanistan border.
Pratt pointed to the recent German case, in which US intelligence played a key role, as evidence that spy agencies are getting much better at sharing information across borders.
In Madrid, the seven acquittals sparked expressions of grief and anger among the black-clad representatives of victims' families in the courtroom. "The killers are walking free," said spokeswoman Pilar Manjon, who lost her 20-year-old son in the bombing. "The verdict seems feeble, and we will appeal to the Supreme Court."
Other relatives, some accompanied by psychologists, wept and condemned the verdict as a bitter disappointment.
- Independent, Reuters
