Terrorism is, at root, the indiscriminate use of violence against civilians for political ends. Even before the deadly attacks on the World Trade Center in New York City on September 11, 2001, it was a significant problem in the United States and wider world. Readers of this book are probably aware of several ghastly and high-profile terrorist incidents that took place in the United States prior to its current “war on terror.” For example, the anti-technology-inspired “Unabomber” (Theodore Kaczynski) sent sixteen letter-bombs to various targets between 1978 and 1995. Timothy McVeigh, a supporter of right-wing, anti–federal government ideology, blew up a federal building in Oklahoma City in 1995 in what was, at the time, the single deadliest act of terrorism in American history. Right-to-life advocates have subjected abortion clinics and their staffs across America to scores of murders, bombings, and arson attacks over the last couple of decades. Assassins’ bullets have taken the lives of four American presidents (Lincoln, Garfield, McKinley, and Kennedy), and a total of fourteen presidents have been the targets of failed assassination attempts. During the first eight months of Barack Obama's presidency, he received an average of thirty death threats a day (Democracy Now, August 4, 2009).

America, however, is not exceptional when it comes to terrorist violence. In fact, no part of the world has been free of this scourge in the modern age. In the United Kingdom, for instance, the Provisional Irish Republican Army (IRA) and its offshoots killed more than 1,800 people in terrorist attacks from 1969 to 2001. In Spain, the Basque separatist group ETA (or Basque Homeland and Freedom) has murdered more than 800 people since launching its bid for independence in 1968. In Sri Lanka, the separatist Tamil Tigers conducted 171 suicide attacks, often involving female bombers, between 1983 and 2000. It is worth noting too that those who practice politics-as-violence often deliberately target advocates of peaceful political protest and politicians who either promote or sign peace treaties.