The group made several attempts at sending its people into the USSR illegally before, during, and after World War II for the purpose of creating an underground revolutionary force in Soviet Russia. The organization, despite the support of foreign intelligence agencies, could not match the powerful network of the OGPU and NKVD. The pre and post war attempts were the least successful, often ending in shootouts with the Soviet authorities, or capture. The war period was the most successful, although there were a high number of casualties who either suffered at the hands of the German Gestapo, or sleeper cells which were uncovered by the Soviet secret police.