"The debate over appeasement – the attempt by Britain and France to avoid war by making "reasonable" concessions to German and Italian grievances during the 1930s – is as enduring as it is contentious. Condemned, on the one hand, as a "moral and material disaster", responsible for the deadliest conflict in history, it has also been described as "a noble idea, rooted in Christianity, courage and common-sense". Between these two polarities lies a mass of nuance, sub-arguments and historical skirmishes. History is rarely clear-cut, and yet the so-called lessons of the period have been invoked by politicians and pundits, particularly in Britain and the United States, to justify a range of foreign interventions – in Korea, Suez, Cuba, Vietnam, the Falklands, Kosovo and Iraq (twice) – while, conversely, any attempt to reach an accord with a former antagonist is invariably compared with the infamous 1938 Munich Agreement. When I began researching this book, in the spring of 2016, the spectre of Neville Chamberlain was being invoked by American conservatives as part of their campaign against President Obama's nuclear deal with Iran, while today the concept of appeasement is gaining new currency as the West struggles to respond to Russian revanchism and aggression. A fresh consideration of this policy as it was originally conceived and executed feels, therefore, timely as well as justified."