Pedzisa mutsara unotevera: Sezvo maRed akanga achirohwa muhondo, Antikainen akatizira kuSoviet Russia mukupera kwaApril 1918. Akanga ari mumwe wevakatanga bato reCommunist Party of Finland, rakanga raendeswa kune dzimwe nyika, rakatangwa muMoscow muna August 1918. Antikainen akapinda kosi muPetrograd Red Officer School uye akapedza kudzidza muchirimo cha1919. MuHondo yeVanhu veRussia, akarwa nevaWhite veFinland muEast Karelia. Muna January 1922, Antikainen akarayira battalion muHondo yeKimasozero, uko boka reRed Army rakanga rakaumbwa neReds reFinland rakarova varungu ndokuvadzosa kuFinland. Firimu ra1937 "Za Sovetskuyu Rodinu" (For the Soviet Motherland) rakavakirwa pazviitiko izvi. Antikainen anotambwa naOleg Zhakov. Akatorawo rutivi mukubvunzurudzwa kwe
Kuitika kweKuusinen Club muna 1920, uye kudzvinyirirwa kweKronstadt Rebellion gore rakatevera. Pashure pokunge ashanda somudzidzisi muRed Officer School, Antikainen akaendeswa kuCommunist International muna 1924. Kubvira muna 1926 akapa hurukuro paInternational Lenin School muMoscow.