According to Kinzer, for most Americans, the crisis in Iran became just part of the conflict between Communism and "the Free world". "A great sense of fear, particularly the fear of encirclement, shaped American consciousness during this period. ... Soviet power had already subdued Latvia, Lithuania, and Estonia. Communist governments were imposed on Bulgaria and Romania in 1946, Hungary and Poland in 1947, and Czechoslovakia in 1948. Albania and Yugoslavia also turned to communism. Greek communists made a violent bid for power. Soviet soldiers blocked land routes to Berlin for sixteen months. In 1949, the Soviet Union successfully tested a nuclear weapon. That same year, pro-Western forces in China lost their Civil War to communists led by Mao Zedong. From Washington, it seemed that enemies were on the march everywhere." Consequently, "the United States, challenged by what most Americans saw as a relentless communist advance, slowly ceased to view Iran as a country with a unique history that faced a unique political challenge." Some historians, including Douglas Little, Abbas Milani and George Lenczowski have echoed the view that fears of a communist takeover or Soviet influence motivated the U.S. to intervene.