Ka kammala wannan jumla: Yayin da 'yan Red suke shan kashi a yaƙin, Antikainen ya gudu zuwa Rasha ta Soviet a ƙarshen Afrilu 1918. Ya kasance ɗaya daga cikin waɗanda suka kafa Jam'iyyar Kwaminis ta Finland da ke gudun hijira, wanda aka kafa a Moscow a watan Agusta 1918. Antikainen ya yi karatu a makarantar Petrograd Red Officer School kuma ya kammala karatunsa a cikin bazara na 1919. A cikin Yakin basasa na Rasha, ya yi yaƙi da Fararen Finnish a Gabashin Karelia. A watan Janairun 1922, Antikainen ya jagoranci rundunar soja a yakin Kimasozero, inda rundunar sojojin Red Army da suka hada da Reds na Finnish suka doke fararen fata kuma suka tura su zuwa Finland. Fim din 1937 "Za Sovetskuyu Rodinu" (Domin Gidan Gida na Soviet) ya dogara ne akan abubuwan da suka faru. Antikainen yana wasa da Oleg Zhakov. Ya kuma shiga cikin binciken da aka yi game da
Kuusinen Club Incident a cikin 1920, da kuma dakile Kronstadt Rebellion shekara guda daga baya. Bayan ya yi aiki a matsayin malami a Makarantar Jami'in Red, Antikainen ya koma Kungiyar Kwaminisanci ta Duniya a 1924. Tun daga 1926 ya ba da laccoci a Makarantar Lenin ta Duniya a Moscow.