Transatlantic security cooperation: counterterrorism analysis and policy in the post 9/11 era

The transatlantic relationship between the United States of America and Europe has traditionally been one of the closest alliances throughout modern history. The relationship remained close even after the loss of the common Soviet threat and into the twenty-first century. However, the morning of September 11, 2001 would become the turning point in the transatlantic relationship that highlighted fundamental differences in threat perceptions between the two allies. 9/11 introduced a new common threat to the twenty-first century—international religious-based terrorism. Despite the emergence of a new common threat, divergences in threat perceptions, legitimacy of force, and politicomilitary cultures have wedged themselves deep into the current transatlantic relationship. The European Union and the United States fundamentally differ on how to address the threat of terrorism. This raises the question: Why do the European Union and the United States differ in their respective threat analyses of modern terrorism and in their policies to address it