In 1943, he deserted and went to fight with the Greek partisans as part of the Anti-Fascist Committee for a Free Germany in Greece and later, its representative for the XIII Greek People's Liberation Army (ELAS) Division.
In 1943, he deserted and went to fight with the Greek partisans as part of the Anti-Fascist Committee for a Free Germany in Greece, which he co-founded with Falk Harnack. Later, he became its representative for the XIII Greek People's Liberation Army (ELAS) Division.