Tolstoy’s vast novel follows the Rostóvs, Bolkónskis, Bezúkhovs, soldiers, peasants, and emperors through the Napoleonic wars, from salons and balls to Austerlitz, Borodinó, burning Moscow, captivity, grief, marriage, and the long argument over who really makes history. It is two books at once, and refuses to choose: a novel about families under pressure, and a…