オーデル・ナイセ線
On 1 May 1956, the West German Foreign Minister Heinrich von Brentano admitted during a press conference in London that the Federal Republic's stance on the Oder–Neisse line was "somewhat problematic", and suggested that the Federal Republic should recognize the Oder–Neisse line in exchange for the Soviet Union allowing German reunification. Brentano's remark caused such an uproar with the expellee leaders arguing that he should resign, that Adenauer was forced to disallow his foreign minister, and Brentano only kept his job by claiming that he was misquoted by the British press. In private, Brentano was willing to accept the Oder–Neisse line as the price of reunification, and was not misquoted in London as he claimed afterwards. Away from the public limelight in a conversation with the Canadian ambassador Charles Ritchie in June 1956, Brentano called the leaders of the expellee groups "unteachable nationalists" who had learned nothing from World War II, and who did not have the right to control the Federal Republic's policy towards Eastern Europe by vetoing policy changes they disliked. Brentano's press conference was meant by Adenauer to be a trial balloon to see if the Federal Republic could have a more flexible policy towards Eastern Europe. The furious protests set off by Brentano's press conference convinced Adenauer that he did not have the domestic support for such a policy, and that the current policy of opposing the Oder–Neisse line would have to continue. This caused considerable disappointment with Adenauer's Western allies, who had been applying strong pressure behind the scenes and would continue to apply such pressure for the rest of the 1950s for Bonn to recognize the Oder–Neisse line. This pressure become especially acute after the "Polish October" crisis of 1956 brought to power Władysław Gomułka as Poland's new leader. Gomułka was a Communist, but also a Polish nationalist, and it was believed possible in Washington that a split could be encouraged between Moscow and Warsaw if only Bonn would recognize the Oder–Neisse line. Because the Federal Republic's refusal to recognize the Oder–Neisse line together with the presence of such Nazi-tainted individuals like Theodor Oberländer in Adenauer's cabinet, Gomułka was obsessed with the fear that one day the Germans would invade Poland again, which would mean a return to the horrors of the German occupation.