A- orchestrating politically motivated mass murders
The mass murders became the dictator's choice in eliminating any kind of political opposition.They were significant in 1936 til 1938, when the USSR was adoptating the stalinist model. The series of mass murders targeted former Communist Party officials, landlords and even high ranked members of the Red Army. Stalin developed a paranoia where, everything became subject of strict surveillance, and suspicios of its Cabinet members. Many other repressive methos included imprisionment and forced labor work in the Gulags located in harsh Siberian condtions.
B- The U.S.S.R. had little international trade
The Soviet Union had a large enery supply inland and many raw natural sources. Since its creation it was designed to operate with a policy of self sufficiency.
The currency of the USSR was not widely accepted by the Capitalists so it also did not became a priority on the agenda to foster cooperation. In this sense the Soviet bloc resorted to regional cooperation among the frontiers and with countries that embraced socialist ideology. The existing amount of exports and imports that can be considerated for the international trade were mostly with the Eastern european satellite states.