In return for the release of the last German prisoners of war in 1955, the Federal Republic established diplomatic relations with the USSR, but refused to recognize East Germany and broke off diplomatic relations with countries (e.g., Yugoslavia) that established relations with the East German régime. Adenauer was also ready to consider the Oder-Neisse line as the German border in order to pursue a more flexible policy with Poland but he did not command sufficient domestic support for this, and opposition to the Oder-Neisse line continued, causing considerable disappointment among Adenauer's Western allies.