By early 1959, Adenauer came under renewed pressure from his Western allies, to recognize the Oder-Neisse line, with the Americans being especially insistent. Adenauer gave his "explicit and unconditional approval" to the idea of non-aggression pacts in late January 1959, which effectively meant recognising the Oder-Neisse line, since realistically speaking Germany could only regain the lost territories through force. After Adenauer's intention to sign non-aggression pacts with Poland and Czechoslovakia became clear, the German expellee lobby swung into action and organized protests all over the Federal Republic while bombarding the offices of Adenauer and other members of the cabinet with thousands of letters, telegrams and telephone calls promising never to vote CDU again if the non-aggression pacts were signed. Faced with this pressure, Adenauer promptly capitulated to the expellee lobby.