Does terrorism work? Why we need to answer the question – however difficult it is

In his new book, Richard English attempts to answer a question many would prefer not to contemplate: does terrorism work? Are its perpetrators right to judge that the only way to achieve the changes they want is through violence? English goes on focus on four of the most significant terrorist organisations of the last half-century: al-Qaida, the Provisional IRA, Hamas, and ETA. This extract confronts the difficult truth that terrorists tend to show the same levels of rationality as other people.