Amis, likewise, has a message that deserves to be heard in a Europe where the victims of the Holocaust tend increasingly to be identified with the perpetrators. His decision to write a second Shoah novel nearly a quarter of a century after Time's Arrow suggests that he understands why it has never been more important to understand how  the Jewish people were all but annihilated on the Continent. Despite the ziggurat of books on the subject, Amis cannot leave it alone. He dedicates this public and private tribute "to those who survived and to those who did not . . . and to the countless significant Jews and quarter-Jews and half-Jews in my past and present". The novel is one man's remonstration against the past — and a warning that the world could turn a blind eye to such murder again. For, as Szmul observes, "it is my feeling that the world has known for quite some time. How could it not, given the scale?"

It is not as though the continuities between the architects of the Final Solution and today's anti-Zionists were unknown. According to Bettina Stangneth's new book, Eichmann before Jerusalem (Bodley Head, £25), in his postwar Argentine exile Eichmann revelled in role-reversal, depicting the Germans as victims and blaming the Zionist leader Chaim Weizmann for the war, while denouncing the new state of Israel for its "crimes" against the Arabs: "Where, where are the gallows now, for these war criminals and perpetrators of crimes against humanity?" There is rich material here for a sequel to The Zone of Interest, if only as an antidote to those who echo Eichmann today.

They are two of the finest living writers in English, but neither Ian McEwan nor Martin Amis is able to escape from the limitations of their generation. Confronted by religion or ideology, both take refuge in a very Anglo-Saxon empiricism: give us the facts and the decent thing to do will be obvious. But whether their sense of decency is up against a rigid faith inimical to modernity or a radical evil that annihilates millions, the moral foundations of this sensibility are precarious, based on not much more than a vague intuition that taking the right side is always self-evident and self-explanatory. Yet in the language of the Third Reich, "decent", anständig, was just as common a term of approbation as it is in English today. Indeed, Amis depicts the Nazi notion of decency in the character of Golo's aunt, Gerda Bormann, with her "the stupid beauty". A sense of decency did not bring the Germans, even the best of them, to their senses until it was too late. Decency has not rendered hundreds of third-generation British Muslims immune to the allure of Islamic State. Decency is not enough.