During the 1920s many youthful western communist idealists had grown up seeing the Soviet Union under its communist leadership as humanity's best hope for the future. Käthe Niederkirchner arrived ready to embrace her new homeland, and after arriving in Moscow in many ways she was able to benefit from the new opportunities, even though she never returned to a career in tailoring. She intensified her study of Marxism–Leninism and other important subjects. She appears to have been able to support herself without difficulty. For a while she worked as a German-language presenter for Moscow Radio. However, the Soviet Union was also affected by growing political tensions. At the height of the Stalinist purges, her older brother Paul Niederkirchner was arrested in Moscow by the security services. He was shot dead on 19 October 1938. The situation changed further in June 1941 when the German government unexpectedly (to most) repudiated an important existing non-aggression agreement launched a massive invasion of the Soviet Union. In 1941 Käthe Niederkirchner married , a communist hero of the recently concluded Spanish Civil War. However, it is unclear whether they were ever able to live together, since in the chaos of war party authorities moved Wieland, who had been badly wounded in Spain, to a home for invalids in Osh (Kyrgyzstan). One indirect result of the German invasion of the Soviet Union was Soviet sponsorship of the organisation, under the auspices of which Niederkirchner involved herself extensively in training/propaganda work with German prisoners of war. She also undertook intensive training in after-dark parachute jumping and for "underground work" in Germany.