Свободная Германия
After the Nazis came to power, Wolf emigrated with his family to Moscow. In 1938 he made his way to Spain to work as a doctor in the International Brigades. However, he was arrested in France and interned in the concentration camp Le Vernet. In 1941 he gained Soviet citizenship and returned to Moscow where he became a founder of the National Committee for a Free Germany (NKFD).