What is known is that Mr. Abdeslam had been the subject of a worldwide manhunt since November, hiding out in the Molenbeek neighborhood of Brussels where he grew up and easily eluding authorities in a city where police and intelligence agencies are fragmented, fractured by language differences and badly in need of repair, the Editorial Board of The New York Times wrote in its article titled "Steps That Europe Must Take Now After Brussels" on March 23.
Beyond an obvious need to improve policing in Belgium, the European Union must quickly tighten security at airports, in train stations, and in urban metro and intercity rail systems. On Tuesday, the French interior minister, Bernard Cazeneuve, announced that France was ordering 1,600 police officers to guard border crossings and transportation hubs. Germany announced that it, too, was clamping down on its border with Belgium.
Belgium and France have increased counterterrorism efforts. But often, these efforts are plagued by interagency rivalries for legal, practical or territorial reasons. EU members have yet to fully carry out the European Agenda on Security directive, adopted by the European Commission last April, which is specifically intended to improve counterterrorism cooperation among European nations and to criminalize activities like traveling abroad for terrorist purposes.
And even stronger measures won't work unless attention is paid to the causes that make too many young European citizens of immigrant origin vulnerable to the lure of the Islamic State, which claimed responsibility for the Paris and Brussels attacks. The profile that has emerged of the terrorists involved in recent attacks is of young men, born in Europe, who grew up in poor, Muslim-majority immigrant neighborhoods and who had engaged in petty crime and drug dealing before turning to terrorism.
In these neighborhoods, the police are typically seen as threats, which only make apprehending terrorists like Mr. Abdeslam harder. And relentless ethnic profiling by the police and violent raids on Muslim homes and businesses, as have been taking place in France and Belgium since November, have further alienated these communities.
But these communities also hold the key to foiling terrorists. Abdelhamid Abaaoud, the mastermind of the Paris attacks, was found in a rented apartment just outside Paris after his cousin's friend met him and alerted the French police. Likewise, Mr. Abdeslam was, according to the French newspaper Le Monde, apprehended after he called a friend asking for help finding a hide-out, and that friend alerted the police.
The young woman who turned in Mr. Abaaoud has said she lost her home and her job as a result, and is receiving scant support from French authorities. Europe's national witness protection programs, where they do exist, do little to protect witnesses and their families, which discourage cooperation with law enforcement.
While Europe must take urgent action to protect citizens, the key to thwarting terrorism is to build trust with the vast majority of Europe's Muslim citizens, who are, as Britain's home secretary, Theresa May, said on Wednesday, "as concerned as everybody else" with the terrorist threat.
