The FAUD recognized the danger posed by National Socialism at a very early point and responded by preparing for illegal, underground activity. At the last Congress of the FAUD in Easter of 1932 concrete plans were laid down. The Geschäftskommission would be removed to Erfurt and the local associations would, if at all possible, dissolve themselves before any ban was enacted. Small, trusted circles [of FAUD members] were to set up a network to enable further nationwide operations.
In 1933 the FAUD was banned and in March of that year the Berlin office of the Geschäftskommission was searched and a number of functionaries taken into police custody. The union members either joined undeground organizations or emigrated. The underground leadership of the FAUD was eventually moved from Erfurt to Leipzig. In 1936-37 the FAUD launched its resistance efforts while those who had emigrated to Spain came together to form the Gruppe DAS (German Anarcho-Syndicalists), which was an active participant in the Spanish Revolution.
Following the Second World War those Anarcho-syndicalists that had stayed in Germany established the “Federation of Libertarian Socialists” (FFS), which discarded industrial organizing in favour of operating as an “organization of ideas” that attempted to spread libertarian concepts in city and factory councils, as well as in cultural organizations. The FFS published a magazine called “The Free Society,” which reflected the maturity and experience of the movement’s best members. Most of the FFS-Groups dissolved themselves in the 1950s owing to their inability to attract younger members. Those that remained, such as Augustin Souchy and Will Paul, still held interviews and publicized valuable memoirs. In the final years a number of biographies were published, among them those of Helmut Kirschey, Hans Schmitz and Kurt Wafner, who were youths at the start of the 1930s.