Terrorism: A Very Short Introduction examines the historical, ideological, and local roots of terrorist violence and explores terrorism in relation to revolutionary power, nationalism, and religious extremism. Is one person’s terrorist another’s freedom fighter? Is terrorism crime or war? What can we do to stop it? For many, the terrorist attacks of September 2001 changed the face of the world, pushing terrorism to the top of many political agendas. This VSI considers recent changes in terrorism, such as the emergence of ISIS and upsurge in individual suicide action, looking at the impact and consequences of several recent terrorist attacks, and outlining the complex issues related to antiterrorist and counterterrorist measures.