War resumed, involving France and Germany, in September 1939: Schaul was interned at Saint-Jean-de-la-Ruelle near Orléans. He spent the next few years in a succession of internment camps, ending up by 1943 in the camp at Djelfa, a few hundred kilometers to the south of Algiers. The internment camp at Djelfa contained enemies identified by the collaborationist French government, who were mainly Communists, Jews, and former Spanish Civil War International Brigade members. In 1943 Schaul then became a member of a British Labour Corps in Algeria, following the Anglo-American military invasion of the entire region. In 1944 he was able to travel to the Soviet Union, arriving in November of that year. Here he was employed as an instructor for French and Japanese prisoners of war. He was then employed by Moscow's Administrative Head Office for Prisoners of War, working as an instructor at various , notably "Anti-Fascist School 2041" at Talitsa.