Stephen F. Cohen is an American scholar of Russian studies. His academic work concentrates on developments in Russia since the Bolshevik Revolution in 1917 and the country’s relationship with the United States. He is a friend of former Soviet President Mikhail Gorbachev, advised former President George H.W. Bush when the Soviet Union collapsed, and helped Nikolay Bukharin’s widow rehabilitate his name during the Soviet era.
Cohen has authored several books; including, “Rethinking the Soviet Experience: Politics and History Since 1917”, “Buhkarin and the Bolshevik Revolution: A Political Biography, 1888-1938”, and most recently, “Failed Crusade: America and the Tragedy of Post-Communist Russia”.He is also a member of the Council on Foreign Relations.
Source- Wikipedia
http://en.wikipedia.org/wiki/Stephen_F._Cohen