SAARBRUECKEN, Germany -- Shortly after departing this southwestern German city on a Paris-bound train, a mysterious foreigner was pulled aside by police at the French border. The passenger claimed to be Palestinian, but carried no identification. He wouldn't say where he was going, or why.
Assuming they had caught an illegal immigrant looking for a better life in Europe, German authorities jailed the Arabic-speaking man in June 1999 and prepared to deport him. But they were unable to confirm his identity or figure out where to send him, so they moved him to a loosely supervised asylum camp for illegal immigrants. Officials there paid little attention when he vanished two weeks before the Sept. 11, 2001, terrorist attacks in the United States.
Italian police display photographs of Rabei Osman Sayed Ahmed, left, also known as "Mohamed the Egyptian," or Mohamed Fayad, and another unidentified man.
(Stefano Rellandini -- Reuters)
The man who would later be code-named "Mohamed the Egyptian" by his Islamic radical friends resumed his illegal travels across Europe in 2001, taking advantage of the continent's open borders to move freely among Germany, Spain, France, Italy and possibly other countries.
Over the next three years, investigators say, he recruited volunteers for suicide missions, frequented fundamentalist mosques and played a key role in planning the biggest terror attack on European soil, the train bombings in Madrid on March 11 this year.
All along, Mohamed -- whose legal name is Rabei Osman Sayed Ahmed -- was able to dodge police and counterterrorism officials in at least three countries. They repeatedly put him on watch lists under a variety of names, but failed to figure out what he was up to, according to interviews with European investigators and a review of court and immigration documents.
"I know who they are, but they don't know who I am," the former Egyptian army officer said to a friend in Milan this past June, shortly before he was arrested by Italian police, who had been recording his conversations. "You confuse them, they won't know where you came from. . . . You're clandestine, but you move around with no problem."
The case highlights Europe's weakest defense in its fight against terrorism: As the continent removes internal barriers to trade and travel, Islamic militants find it easier to move around undetected. When they do attract notice, cell members can often stay a step ahead of the law by changing their names or slipping across borders, aided by long-standing bureaucratic and legal obstacles that prevent European counterterrorism officials from working together more closely.
"They are able to exploit the weaknesses that exist in our system," said Joerg Ziercke, president of the Bundeskriminalamt, Germany's federal law enforcement agency. "They change routes, go across borders. We must close the gaps that we have in our information systems, and we must ensure that terrorists do not use one country as a haven while they are acting in another country."
European leaders have moved to address the vulnerabilities by adopting such measures as common legal standards that make it easier to issue arrest warrants and extradition orders across the continent. But they have had a tough time reaching consensus on many other proposed reforms. Europe has also struggled to overcome resistance among counterterrorism agencies to share sensitive information with neighboring countries or cooperate on prosecutions.
For instance, France has been trying for nine years to extradite Rachid Ramda, a suspect in the 1995 fatal bombing of a Paris Metro station. Ramda is in custody in London, but his case remains tied up in the British courts.
Another breakdown in cooperation surfaced last month, when Spanish police said the ringleader of a cell suspected of plotting to blow up the Supreme Court building in Madrid was being held in a Swiss jail. At first, Swiss authorities denied they had custody of the suspect, Mohamed Achraf, but then acknowledged they did.
Swiss intelligence officials later said they had suspected Achraf of ties to Islamic radicals in Spain but didn't notify Swiss police or the Spanish government. Swiss Justice Minister Christoph Blocher blamed the mix-up on "an information breakdown."
Antonio Vitorino, former European commissioner for justice and home affairs, called the Madrid bombings "a wake-up call" that underscores the need to eliminate old rivalries among the many intelligence and law enforcement agencies in Europe that fight terrorism.
"We cannot fix this overnight," Vitorino said to a group of journalists at a dinner in Brussels last summer, shortly before leaving office. "The sharing of intelligence among member states is still far from desirable. . . . We Europeans are all equally targeted by the terrorist threat, and we all should be equally involved in fighting it."