Certain noises, many aspects of turbulence, and almost all aspects of finance exhibit a level of temporal and spatial variability whose "wildness" impressed itself vividly upon the author, Benoit Mandelbrot, in the early 1960's. He soon realized that those phenomena cannot be described by simply adapting the statistical techniques of earlier physics, or even extending those techniques slightly. It appeared that the study of finance and turbulence could not move forward without the recognition that those phenomena represented a new second stage of indeterminism. Altogether new mathematical tools were needed. The papers in this Selecta volume reflect that realization and the work that Dr. Mandelbrot did toward the development of those new tools.

The first major book on ISIS to be published since the group exploded on the international stage in summer 2014. Drawing on their unusual access to intelligence sources and material, law enforcement, and groundbreaking research into open source intelligence, Stern and Berger outline the origins of ISIS as the formidable terrorist group it has quickly become. 'State of Terror' delves into the 'ghoulish pornography' of pro-jihadi videos, the seductive appeal of 'jihadi chic' and the startling effectiveness of the Islamic State's use of social media as a means of luring and recruiting citizens from countries such as the United States, Great Britain, and France-using recent examples such as Douglas McCain, the American citizen from Minnesota who joined ISIS and died in combat fighting on the side of the Islamic State. Although the picture Stern and Berger paint is bleak, 'State of Terror' also offers well-informed thoughts on potential government responses to ISIS - most importantly, emphasizing that we must alter our present conceptions of terrorism and react to the rapidly changing jihadi landscape, both online and off, as quickly as the terrorists do. 'State of Terror: Jihad in the 21st Century' is not only a compelling account of the evolution of a terrorist organization, but also a necessary book that attempts to answer the question of what our next move - as a country, as a government, as the world - should be.

What extremism is, how extremist ideologies are constructed, and why extremism can escalate into violence. A rising tide of extremist movements threaten to destabilize civil societies around the globe. It has never been more important to understand extremism, yet the dictionary definition-a logical starting point in a search for understanding-tells us only that extremism is "the quality or state of being extreme." In this volume in the MIT Press Essential Knowledge series, J. M. Berger offers a nuanced introduction to extremist movements, explaining what extremism is, how extremist ideologies are constructed, and why extremism can escalate into violence. Berger shows that although the ideological content of extremist movements varies widely, there are common structural elements. Berger, an expert on extremist movements and terrorism, explains that extremism arises from a perception of "us versus them," intensified by the conviction that the success of "us" is inseparable from hostile acts against "them." Extremism differs from ordinary unpleasantness-run-of-the-mill hatred and racism-by its sweeping rationalization of an insistence on violence. Berger illustrates his argument with case studies and examples from around the world and throughout history, from the destruction of Carthage by the Romans-often called "the first genocide"-to the apocalyptic jihadism of Al Qaeda, America's new "alt-right," and the anti-Semitic conspiracy tract The Protocols of the Elders of Zion. He describes the evolution of identity movements, individual and group radicalization, and more. If we understand the causes of extremism, and the common elements of extremist movements, Berger says, we will be more effective in countering it.

They are Americans, and they are mujahideen. Hundreds of men from every imaginable background have walked away from the traditional American dream to volunteer for battle in the name of Islam. Some have taken part in foreign wars that aligned with U.S. interests, while others have carried out violence against Westerners abroad, fought against the U.S. military, and even plotted terrorist attacks on American soil. This story plays out over decades and continents: from the Americans who took part in the siege of Mecca in 1979 through conflicts in Lebanon, Afghanistan, and Bosnia, and continuing today in Afghanistan and Somalia.Investigative journalist J. M. Berger profiles numerous fighters, including some who joined al Qaeda and others who chose a different path. In these pages he portrays, among others, Abdullah Rashid, who fought the Soviets in Afghanistan; Mohammed Loay Bayazid, who was present at the founding of al Qaeda; Ismail Royer, who fought in Bosnia and Kashmir, then returned to run training camps in the United States; Adam Gadahn, a Jewish Californian who is now al Qaeda s chief spokesman; and Anwar Awlaki, the Yemeni-American imam with links to 9/11 who is now considered one of the biggest threats to America s security.