… is from page 103 of Johan Norberg’s 2016 volume, Progress (footnote deleted; link added):
Contrary to popular belief, terror is a very inefficient way of accomplishing ideological goals. For a long time, it was considered efficient because of the success of violent anti-colonial campaigns, but opposition to colonialism succeeded whether it was violent or not. Violent campaigns in general are great failures. The political scientist Audrey Cronin looked at 457 terrorist groups active since 1968. None of them managed to conquer a state and ninety-four per cent of them failed to secure even one of their operative goals. The typical terrorist organization survived only for eight years, partly because the attacks on civilians alienated the population that the group wanted support from: ‘terroist violence contains within itself the seeds of repulsion and revulsion. Violence has an international language, but so does decency’.
So it seems that the only way for terrorists to win is if its victims overreact, dismantle civil liberties and blame whole groups for the actions of a few. Doing so stirs up the very conflicts the terrorists seek and makes it easier to recruit terrorists and continue the battle.