 At its 6th Congress in July 1928, Stalin informed delegates that the main threat to socialism came not from the right but from non-Marxist socialists and social democrats, whom he called "social fascists"; Stalin recognised that in many countries, the social democrats were the Marxist-Leninists' main rivals for working-class support.This preoccupation with opposing rival leftists concerned Bukharin, who regarded the growth of fascism and the far right across Europe as a far greater threat.After Bukharin's departure, Stalin placed the Communist International under the administration of Dmitry Manuilsky and Osip Piatnitsky.