 On 9 November 1945 the Protection Association of German Authors was reinstated under authority from the Soviet occupation forces in the eastern part of Berlin, now as a division of the Free German Trade Union Federation, and Birkenfeld was installed as a member of its executive.He retained this function, as the political and economic division of the city (and of the country) progressively became more visible and permanent, till 1949.In his approach to former Nazis, Birkenfeld took a hard line.