 In 1950, together with Theodor Plievier and , Birkenfeld called for the separation of the from the "Becker Group" which represented the organisation in what had become, formally in October 1949, the separate German Democratic Republic (East Germany).This led directly to the establishment in 1951 of a separate West German PEN organisation under the presidency of Erich Kästner.Birkenfeld worked as a political commentator with the Broadcasting Service in the American Sector ("RIAS") (of Berlin).