Although knowledge and traditions of fighting against terrorism have existed in Europe since the 19^th century, the crisis that has developed in the early 21^st century seems very particular, as it has both internal and external origins. This contribution about terrorism trends in Europe is based on a year-long research seminar, using the foresight bifurcations method, organized during the 2015–2016 foresight course at the University of Paris-Diderot. The work, entitled Counter-terrorism in Europe 2030, managing efficiency and civil rights, describes and analyses trajectories of terrorism and counterterrorism in Germany, United Kingdom and Spain, in comparison with the French and Belgian systems, which have been hit hard in 2015 and 2016. It aims to define long-term issues and outline some answers to the present terrorism challenges.