From the IRA to the Islamic State: The Evolving Terrorism Threat in Europe


Europe faces a significant threat from terrorism, particularly from Islamic extremists and far-right groups. Europe’s challenges with terrorism have largely gone unnoticed in the United States, whose strategy documents like the U.S. Department of Defense’s National Defense Strategy have shifted away from counterterrorism and toward competition with state competitors like China, Russia, Iran, and North Korea. In addition, Europe’s increasingly aggressive approach to terrorists—including prosecuting individuals for planning to travel abroad to join terrorist groups, censoring extremist Internet material, punishing Internet companies that fail to remove extremist material, and improving intelligence cooperation—have also largely gone unnoticed in the United States. This report takes a renewed look at Europe and compiles new data on the threat to Europe. It also examines the counterterrorism response by European governments, especially the United Kingdom and France.

Seth Jones holds the Harold Brown Chair, is director of the Transnational Threats Project, and is a senior adviser to the International Security Program at CSIS. Boris Toucas is a French diplomat. When the French section of this report was researched and written, he was a visiting fellow with the Europe Program at CSIS. Maxwell B. Markusen is the associate director and an associate fellow of the Transnational Threats Project at CSIS.

The authors would like to thank the Diana Davis Spencer Foundation (DDSF) for their support to CSIS.

Seth G. Jones
Senior Vice President; Harold Brown Chair; and Director, International Security Program

Maxwell B. Markusen

Boris Toucas