The Hallstein Doctrine, named after Walter Hallstein, was a key doctrine in the foreign policy of the Federal Republic of Germany (West Germany) after 1955. As usually presented, it prescribed that the Federal Republic would not establish or maintain diplomatic relations with any state that recognized the German Democratic Republic (East Germany). In fact it was more nuanced.There was no public official text of the ""doctrine"", but it was explained publicly in a radio interview by its main architect, Wilhelm Grewe. Konrad Adenauer also explained the outlines of the policy in a statement to the German parliament on 22 September 1955.It meant that the Federal German government would regard it as an unfriendly act (acte peu amical) if third countries were to recognize the ""German Democratic Republic"" (East Germany) or maintain diplomatic relations with it – with the exception of the Soviet Union, as one of the Four Powers responsible for Germany. The response to such an unfriendly act was often understood to mean breaking off diplomatic relations, though this was not stated as an automatic response under the policy, and in fact remained the ultima ratio (last resort).Important aspects of the doctrine were abandoned after 1970 when it became difficult to maintain and the Federal government changed its politics towards the German Democratic Republic.