Toulouse was already becoming a focus for German communist exiles who had escaped from camps in southern France, or simply made their way south when the German army invaded France from the north in May 1940. Links were established to French communists who were becoming a leading element in the Résistance movement against the German military occupation in the north and the Pétain puppet government in the south. From the time of his escape Beling was therefore part of a well supported underground activist network. His party role at this time is variously described: according to at least one source he was the German party leader for the Toulouse region, identified by comrades under the party pseudonyms of "Claude" or "Clément". In September 1940 Beling came to an agreement with Maurice Tréand (who was representing the Central Committee of the in their discussions together) which led to the establishment of the so-called sub-section inside the French Résistance organisation. This provided important underpinning for closer collaboration between German communists operating "underground" in occupied France and Résistance comrades, reducing the mutual suspicion which was inherent in the situation. The Résistance was able to provide extensive "infrastructure support", including provision of counterfeit identity documents whereby German communists having acquired the necessary language skills could blend into the surrounding francophone population. Résistance comrades were also often able to arrange hiding places as the German occupation became more oppressive and, especially after 1942, German security service personnel were frequently to be encountered on French streets, even in the so-called "free zone".