Various conditions have facilitated Europe's rise as a 'hub' of global jihad, especially the presence of a nucleus of foreign Islamist activists, a large pool of potential recruits, and the freedom to operate with few, if any, restrictions. The Iraq war has prompted a revival of the jihadist network in Europe. In response, European policymakers need legal reforms, increased institutional cooperation and sustained efforts to engage with European Muslim communities. The threat is both urgent and profound, and it will be necessary to embark on considered long-term strategies which may require European leaders to re-examine some of the tacit arrangements that have allowed European societies to enjoy an unparalleled degree of domestic freedom, peace and prosperity.