Radicalization has become one of the great buzzwords of our time. A Google search for the concept produces more than 1,500,000 hits less than terrorism but equal to political violence and extremism . This may seem surprising, given that the term entered the academic vocabulary just ten years ago. Previous generations of scholars had, of course, been interested in why and how people become extremists, but there was no separate field of inquiry which brought together the many political scientists, historians, area studies and terrorism experts, social-movement theorists, and psychologists...

The 2015 Paris and San Bernardino terrorist attacks heralded the beginning of a new wave of terrorism one rooted in the ongoing conflict in Syria and Iraq that shows the possibility of foreign attackers working with citizens of the country. As ISIS seeks to expand its reach in the Middle East, its territory serves as a training and operations base for a new generation of jihadis. Young people from the West, primarily from Europe, have traveled to join the terror organization, re-emerging as hardened fighters with military training and a network of international contacts. Many have returned...