What is terrorism and can psychology do anything to prevent it?

Terrorism has a long history, which continues to unfold, and takes many forms. Notwithstanding these facts, there is no generally accepted definition of terrorism. I set forth the definitional issues that underlie the current debate about terrorism. By comparing terrorism with various forms of violence, I argue that it is plausible to construe terrorism as crime and, in support of this, I demonstrate why terrorism cannot be morally justified. Next, I cluster various immediate and long-term approaches intended to prevent terrorism, highlighting psychologically based strategies, such as behavioral profiling, teaching tolerance and citizenship, modifying media images of terrorism, and building peace. In order to understand and respond more effectively to 21st-century terrorism, I advocate adoption of a multidisciplinary, contextually sensitive approach.