Salafism is first and foremost a method for the search of the religious truth; a desire to practice Islam exactly as it was revealed by the Prophet. It is a religious method whose influence has spread throughout the Arab world and also in Europe, thanks to the support received from Saudi Arabia and the Gulf States, which have helped expand this peculiar vision of Islam that is very close to Wahhabism. Its influence is on the rise and it has successfully impregnated several Islamist movements, including some sectors of the Muslim Brotherhoods. In Europe, it has become a powerful magnet for generations of young Muslims who suffer identity problems, reject European citizenship, and use their cultural alienation to justify the adoption of a form of universal Islam stripped of its heritage of traditions and adaptable to all societies. Although in principle Salafism is apolitical and opposes violence, it preaches an Islam that calls for cultural rupture with Europe. Moreover, its principles and textual references coincide with those of fighting Salafism and its followers have therefore become the preferred targets of jihadi recruiters. The fighting version of Salafism has also become the core ideology of the global jihadism sponsored by al-Qa'ida and the radical utopia of Abdallah Azzam. This ideology, aided by the proselytizing work of radical clerics, has led to the emergence in Europe of small groups with the capability to carry out independent terrorist strikes. Europe is no longer a mere logistics base for international jihadism, but a scenario for terrorist action. In the past, Islamist networks operating in Europe restricted their activities to providing logistical support for the cells that planned attacks in other parts of the world. The destruction of its operations base in Afghanistan has caused a transformation of the al-Qa'ida network, which is no longer an organized structure but a trademark or label conferring even greater impact on actions undertaken by local groups. Europe is facing a long term threat that will require not only measures to ensure appropriate integration of its Muslim communities, but also decisive action to confront an ideology that has declared a global war against the West.