The world order built upon the Peace of Westphalia is faltering. State fragility or failure are endemic, with no fewer than one-third of the states in the United Nations earning a "high warning"-or worse-in the Fragile States Index, and an equal number suffering a decline in sustainability over the past decade.1 State weakness invites a range of illicit actors, including international terrorists, globally networked insurgents, and transnational criminal organizations (TCOs). The presence and operations of these entities keep states weak and incapable of effective governance, and limit the possibility of fruitful partnerships with the United States and its allies. Illicit organizations and their networks fuel corruption, eroding state legitimacy among the governed, and sowing doubt that the state is a genuine guardian of the public interest. These networks can penetrate the state, leading to state capture, and even criminal sovereignty.2 A growing number of weak and corrupt states is creating gaping holes in the global rule-based system of states that we depend on for our security and prosperity. Indeed, the chapters of this book suggest the emergence of a highly adaptive and parasitic alternative ecosystem, based on criminal commerce and extreme violence, with little regard for what we commonly conceive of as the public interest or the public good. The last 10 years have seen unprecedented growth in interactivity between and among a wide range of illicit networks, as well as the emergence of hybrid organizations that use methods characteristic of both terrorist and criminal groups. In a convergence of interests, terrorist organizations collaborate with cartels, and trafficking organizations collude with insurgents. International terrorist organizations, such as al-Qaeda and Hezbollah, engage energetically in transnational crime to raise funds for their operations. Prominent criminal organizations like Los Zetas in Mexico and D-Company in Pakistan have adopted the symbolic violence of terrorists-the propaganda of the deed-to secure their "turf." And networked insurgents, such as the Islamic State of Iraq and the Levant (ISIL), the Revolutionary Armed Forces of Colombia (FARC), and the Liberation Tigers of Tamil Eelam (LTTE), have adopted the techniques of both crime and terror.