From Vietnam to Syria, politicians, commentators and journalists have argued both for and against intervention, whether military or humanitarian. Simon Jenkins here presents a provocative and wide-ranging survey of the history of--and the arguments surrounding--intervention in Kosovo, Afghanistan, Iraq, Libya and Syria. Do nations intervene because of right and wrong? Is Western intervention simply a form of 'imperialism-lite'? When is intervention justified? Jenkins traces the evolution of 'liberal interventionism' and shows that scepticism towards it came and comes not just from a growing perception of its failure. Instead, he argues that the past few decades can be characterised as an age of intervention, displaying worrying signs of merely laundering old-fashioned western imperialism and bordering at times on a crusader complex. In the face of recent conflicts--particularly in the Ukraine and with the rise of Islamic State--what can we learn from the miscalculations, mistakes and mendacity of 'the age of intervention'?