PARIS (AP) — The suspect in the recent killings at the Jewish Museum in Brussels is a text book case of the West's longstanding fear — the threat posed by radicalized citizens returning from the battlefields of Syria.
European nations have been slowly fortifying themselves with measures to detect potential jihadists and counter any sinister plots since Syria became a magnet for Westerners. But French-born Mehdi Nemmouche — the first Western citizen returning from Syria and implicated in a major attack — was caught by chance, in a spot check for drugs by a customs official, making a mockery of efforts to counter the threat.
The suspect had slipped through a handful of countries from Asia to Europe in the three months after leaving Syria, a clear sign of the difficulties of tracking returnees.
French police arrested four people on Monday in a sweep against jihadist recruiters, showing the kind of can-do determination President Francois Hollande promised on Sunday after Nemmouche's arrest was made public.
Whether or not he was the shooter, Nemmouche, 29, was a dangerous man: When he was arrested Friday at the Marseille bus station he was heavily armed, carrying a large supply of ammunition and a banner of Syria's most notorious fighting group, the Islamic State of Iraq and the Levant. His camera contained a video showing the weapons and clothes appearing to match those of the killer in the furious minute-long May 24 museum attack, which left three people dead and one seriously injured. A voice said the video was made because a camera to live broadcast the killings failed to function.
Nemmouche, a delinquent from northern France who spent seven years behind bars, had radicalized in prison, Paris Prosecutor Francois Molins said in announcing the arrest.
Between 1,000 and 1,500 Europeans may currently be fighting in Syria against President Bashar Assad, according to Charles Lister, an analyst with Brookings Doha Center, who drew the estimate from governments and other sources. Each one who returns represents a potential threat, according to official European thinking, and the challenge to track them all is huge. The arrest of the French suspect in the Belgian attack also opens the possibility that a returnee could choose a country to act other than his homeland.
Thomas Hegghammer, an expert on foreign fighters at the Norwegian Defense Research Establishment, says that attacks by single persons are far harder to thwart than large-scale operations.
European governments "are quite well positioned to thwart larger plots involving several people ...," Hegghammer said. "They're not able to stop all the smaller, simpler attacks like the one in Brussels, with one person and a gun."
Nemmouche traveled through more than a half-dozen countries on his trip to and from Syria, Molins said.
A map of arrests and networks linked to jihadists or wannabes would criss-cross Europe and, it appears, dovetail into Morocco and to Turkey, the main destination of Westerns heading to Syria, according to Europol, the European Union's police organization.
In its annual report issued last month, Europol said radicals who travel to fight alongside militants in conflicts like the Syrian civil war are "posing an increased threat to all EU member states on their return."
A leading French criminologist who advised former President Nicolas Sarkozy said that a lack of coordination and data sharing among nations — even within the EU — stunts measures to counter the threat.
"The task is not impossible," he said. "You need greater and better coordination."
A major issue, he said, is that in sharing information "you also share some intelligence about who gave you the information. Protecting a source is a major problem."
Bauer underscored the importance of catching the traveler before he embarks. And this means "early intelligence, early warning, early detection. That is something we don't do," he said.
France feels particularly vulnerable because it has the highest estimated number of youth heading to Syria or fighting there — about 700. It rolled out new measures in April to prevent its citizens and legal residents from joining the jihad and protecting against potential threats posed by returnees. Among them is a plan to adjust the law to allow for confiscation of passports to stop youth suspected of wanting to travel to Syria, Interior Minister Bernard Cazeneuve said at the time. Another measure allows for immediate deportation of foreign residents if linked by police to terrorism overseas.
Withdrawing passports is, perhaps, the most drastic measure to counter the jihadist phenomenon, but some European countries have already done so.
The Dutch government has canceled passports of 11 people, a legal move when authorities can show they have good reason to suspect an individual may harm Dutch national interests while abroad. Britain has also withdrawn passports under a "Royal Prerogative."It doesn't release figures on passport cancellations, but according to the Bureau of Investigative Journalism, Home Secretary Theresa May in 2013 removed the citizenship of 20 individuals, including many who were suspected of planning trips to Syria.
However, softer approaches also are on the books in Britain and elsewhere.
A brief look at several European programs to prevent and counter the phenomenon of Western jihadists in Syria:
France put in place a series of tough-love measures in April that includes a hotline for parents who fear their children are at risk of taking up jihad in Syria. They would be referred to social workers and others. In conjunction with European partners, France plans to increase monitoring of Web sites that post videos and other messages inciting jihadist activities. Such sites remain visible.
The Dutch have an elaborate program to counter the jihadist phenomenon that sent about 100 youth to Syria, of which 20 returned and 10 were killed. Besides canceling 11 passports, an unspecified number of minors have been stopped from leaving, some placed in juvenile detention. The secret service contacts would-be jihadists it detects and tries to dissuade them. Youth at risk can get interventions, some cooperating with imams and other community leaders.
Belgium, which says about 150 of its citizens are in Syria, has set up programs in sensitive towns to improve cooperation among authorities and designated a "prevention specialist" in 29 towns. A national prevention cell brings together police, experts and social workers in an outreach similar to France's proposals.
Britain's long-standing Prevent program liaises with schools, volunteer agencies and other local groups to detect a potential extremist. The police are in charge. It got a recent update by encouraging women to reach out to other women concerned about potential jihadists on the home front.
Some 320 extremists from Germany are currently in Syria, and some 50 have returned, but the authorities maintained a hands-off approach until recently, allowing them to fly out and return without being stopped because terrorism in Syria is difficult to prove. More recently, those suspected of plans to join Syrian jihadist groups are being stopped at airports before they fly out and are tracked upon return, but land routes remain open highways for the perseverant.
Associated Press writers Lori Hinnant in Paris, Gregory Katz in London, Frank Jordans and David Rising in Berlin,Toby Sterling in the Netherlands and Matti Huuhtanen in Helsinki contributed to this report.