A decade ago, counterterrorism analysts around the world fretted about the possibility of European jihadists returning from the wars in Iraq and Afghanistan and finding safe harbor among embittered diaspora communities across Europe. But the al Qaeda “bleed out,” as it was called in counterterrorism circles, never really happened. The group didn’t take hold of North African and Middle Eastern communities in Europe. It failed to attract many of what the group called “clean skins”—Western passport holders able to slip through security without drawing attention.
The Islamic State (ISIS) has achieved in short order what al Qaeda could only dream about. Motivated by a call for jihad in Syria and connected via social media, second- and third-generation Muslim Europeans joined in droves to fight in Iraq and Syria. Their bonds grew tight; their propensity and their thirst for violence was insatiable. After helping build their caliphate in Syria and Iraq, these young European fighters have turned their guns on their homelands, with devastating effect. Brussels, Istanbul, and Paris—the violence has been steady and sustained.
Recent articles in The Wall Street Journal and Foreign Affairs suggest that ISIS is simply following the al Qaeda approach to terrorism in Europe. But such claims are off base. Al Qaeda sought to bring Westerners—clean skins—to terrorist safe havens, where the group would train them to follow detailed plans to attack designated high-profile targets. Trained cells and lone infiltrators were deployed back to their homelands in pursuit of al Qaeda’s bidding. These disciples had little autonomy and were directed to strike at high-profile targets. ISIS’ European jihad looks very different from that of its al Qaeda forefathers, and it is far more dangerous for Europe.
ISIS’ greatest advantage in Europe comes from its many years of cultivating foreign fighter networks to Syria. Much has been made of al Qaeda leader Osama bin Laden’s Arab legion fighting in Afghanistan during the 1980s, but that force’s numbers paled