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.