Mezue ahịrịokwu na-esonụ: Onye odeakụkọ na-elekọta mmadụ bụ Willi Eichler nọchiri Nelson dịka onye isi oche nke ISK mgbe ọ nwụsịrị. Eichler na Specht ga-abịanye aka na 1932 "Ọkpụkpọ oku maka ịdị n'otu" ("Dringender Appell für die Einheit") na akwụkwọ akụkọ ISK, "Der Funke". Ọ kpọrọ òkù ka ndị Social Democratic Party (SPD) nke Germany na ndị Communist Party (KPD) mepụta otu òtù dị n'otu nke ndị òtù aka ekpe iji gbochie ndị Nazi. Mgbe ndị
Mmeri ndị Nazi na 1945, ISK jikọtara ya na SPD na nkwekọrịta ahụ zutere na 10 Disemba 1945, n'etiti onye isi oche nke ISK (Will Eichler) na onye isi oche nke SPD (Kurt Schumacher). Agbanyeghị, ISK gara n'ihu na-arụ ọrụ na nguzogide megide Nazism. E mepụtara ngalaba ISK nke Britain (nke dị site na 1920s ruo 1950s) na United Kingdom a na-akpọ Socialist Vanguard Group.