If Not Now, When? is rooted in historical events and draws on Levi's own experiences in Auschwitz and as a displaced person after the war, on the stories of partisans he met, and on secondary sources. It gives us a feel for the broad spaces and the marshes and forests, the scattered skirmishes of a spread-out war, and the uneasy relationships between civilians and different partisan groups, with trade and exchange persisting even in desperate conditions, but with Russians and Poles not always friendly to Jews.
Levi is a novelist, however, not a historian. It is individuals who are at the core of his work — Mendel first and foremost, but others are also given substance — and their relationships as they seek companionship, romance and fleeting happiness. Some struggle with doubt and despair, and in Mendel's more ruminative moments we see the philosophical quandry facing those who have lost everything and must find new goals, new purposes. But this doesn't dominate the story. If Not Now, When? exhibits Levi's familiar restraint, his disdain for the flamboyant or dramatised, but it is a fast-moving novel, a simple but powerful story of human endurance and struggle in a hostile world.