The capstone of the New Order and the ­ultimate expression of Hitler’s fantasies was the mass murder of Jews. Mazower concurs with contemporary historians, such as Ian Kershaw and Saul Friedländer, in describing how the key to this crime was once again opportunity. In the early stages of the war, Jews were to be obliged to emigrate collectively to Madagascar.

The capture of territories inhabited by large numbers of Jews made possible the alternative — mass killings in hidden locations. By 1942, Joseph Goebbels could confide in his diary that the Nazis’ implementation of “rather barbaric measures not to be described here more precisely; not much is left of the Jews”.

Peace gave liberal democracy a second chance, but several national frontiers changed once more, and minorities underwent compulsory population exchanges amid much suffering and injustice. One ­unforeseen consequence of the war was the foundation of the State of Israel, in 1948, and another was the total collapse of Europe’s global moral authority, its empires and indeed its previous pre-eminence in the world.

Mazower catches the broad historic sweep of these events, and illustrates it with telling details taken from a very large range of sources. Whether today’s Europe is really able to repair so destructive a past is this book’s unspoken question.