Much of the earliest critical reaction to War and Peace focused on how well Tolstoy had accurately portrayed historical events in Russia. Although Tolstoy took great pains to research the historical documents, he did not feel obliged to stick firmly to the common historical interpretations. Still, since many critics had lived through the events described, while many others had grown up hearing about them, it was difficult for critics to not talk about how Tolstoy's version related to their own. In general, they found the novel to be quite accurate.

Some critics took exception with the way that Tolstoy had presented the military commanders as less instrumental in the outcome of the war. At the other extreme were those critics who faulted Tolstoy for failing to improve the social consciousness of the time. Edward Wasiolek explains that radical critic Dmitry Pisarev commented that the first half of the book, which was all that was published before his death, was "a nostalgic tribute to the gentry."

Wasiolek also relates the comments of N. K. Strakhov, whose criticism of the novel he describes as "the best criticism on War and Peace at the time, and possibly the best in Russian since." He credits Strakhov for his appreciation of the psychology of the novel and for recognizing the fact which is commonly accepted today, that Tolstoy's greatness was in being able to render a full character in just a few words. Strakhov appreciated the novel, but he could not fully account for its greatness: as he noted, "among all the various characters and events, we feel the presence of some kind of firm and unshakable principle on which the world of the novel maintains itself."

The ambiguity of that "firm and unshakable principle" was what earned the book a lukewarm reception when it was translated into English. Matthew Arnold, in his review for Fortnightly Review, noted that Tolstoy wrote about "life" but not "art." Perhaps the most lasting criticism by an English-speaking author was that of novelist Henry James. In his introduction to the book, The Tragic Muse, as in the introductions to most of his works, James considered philosophical matters of art. Considering Tolstoy and Alexandre Dumas, the French author of The Three Musketeers and The Count of Monte Cristo, James wondered, "What do such large loose baggy monsters, with their queer elements of the accidental and the arbitrary, artistically mean?" He went on to assert that "there is life and life, and as waste is only life sacrificed and thereby prevented from 'counting,' I delight in a deep-breathing economy and organic form."

After the Russian Revolution in 1917, Tolstoy fell into favor with new Communist government. Up until then, his literary reputation was maintained by people who had known him (he died in 1910) and a few stalwart fans. In a 1924 article, the author Maxim Gorky relates Lenin talking about War and Peace in the Kremlin in 1918: '"He, brother, is an artist!...Whom could one put next to him in Europe? Then [Lenin] answered himself 'No one.'" It was not long before Tolstoy studies went beyond personal reminiscences to intellectual scholarship in Russia. At a time when many other significant Russian authors were banned because of their views, Tolstoy was embraced as a foresighted nobleman who wrote about the value of common people and the arbitrary nature of class distinctions.

Today, Tolstoy's career is divided into two eras: the spiritualism of the later novellas and the sweeping romances of the earlier novels, such as War and Peace and Anna Karenina. Critics perceive within War and Peace one phase of his life leading into the other: how the prodigious novelist of the 1860s and 1870s evolved into the thoughtful spiritual man he was by the turn of the century. There is no question of Tolstoy's greatness today.