The nature and goals of terrorist organizations have changed profoundly since the Cold War standoff among the U.S., Soviet, and Chinese superpowers gave way to the current "polyplex" global system, in which the old rules of international engagement have been shattered by a new struggle for power among established states, non-state actors, and emerging nations. In this confusing state of global disorder, terrorist organizations that are privately funded and highly flexible have become capable of carrying out incredibly destructive attacks anywhere in the world in support of a wide array of...