Stephen Cohen, historian of the Russian Revolution and commentator on Russian-American relations, passed away earlier this year.

His most important and enduring contribution was a groundbreaking 1973 biography of Nikolai Bukharin. Cohen was born in 1938, the same year Bukharin was executed by Stalin, and his work encouraged socialists and historians to engage with both the neglected legacy of one of the true geniuses of the Russian Revolution and larger interpretive questions about the rise of Stalinism.

Taking issue with the anti-Communist narrative of the Russian Revolution leading inexorably to Stalinism, Cohen argued that Bolshevism “was a diverse movement” with “endless disputes over fundamental issues.” The 1920s was a “golden era” of Marxist thought, with “contrary theories and rival schools.” Bukharin, “rightly considered the favorite of the whole party,” according to Lenin, was at the center of many of these controversies. More than a political biography, Bukharin and the Bolshevik Revolution: A Political Biography, 1888–1938 offered “a way of reexamining the Bolshevik revolution” and the formative years of Soviet history.