He pointed out that both sides should be bound by Wilson's Fourteen Points, but ultimately the tenor of his speech convinced the allied delegation that Germany would maintain an aggressive posture and this contributed to the allies insistence on harsh terms for the Germans in the settlement agreement. Brockdorff-Rantzau led the effort by the German delegation to write up some counter proposals that were handed over to the Allies on 29 May (and caused consternation back in Berlin). He argued against what he thought to be a false dichotomy between "to sign" or "not to sign", and considered written negotiations (the Allies had refused to negotiate face to face) an alternative to make the onerous peace less unfair and dishonouring to Germany. After it became obvious that the Allies were not willing to make any changes (save in very minor matters) to the original Treaty draft and that Germany was likely to sign it nonetheless, he resigned his post on 20 June 1919 together with Scheidemann and Otto Landsberg, protesting the signature of what he thought of as a "Diktat". Over the next years Brockdorff-Rantzau took an active interest in foreign policy issues and went public several times with arguments for a revision of the Treaty and the establishment of a more rational law of nations. On 15 July 1922, he penned a secret memo to Friedrich Ebert, warning of the dangers associated with the Treaty of Rapallo as this would cause the Western powers military concerns. He argued that a policy of playing off the great powers against each other, like Bismarck had done, was not possible any more. However, appointed as ambassador to the Soviet Union in November 1922, he favoured a rapproachment between the two countries without sacrificing German links to the west. His opposition to military cooperation with the Soviets led to confrontations with the head of the Reichswehr, Hans von Seeckt, as well as with Chancellor Joseph Wirth. He was very critical of the Locarno Treaties, which brought Germany closer to France and were resented by the Soviet leadership. Brockdorff-Rantzau managed to win Soviet agreement to the Treaty of Berlin in April 1926 that established a relationship of neutrality and nonaggression between the two countries. He felt that this pact restored a balance between German links to east and west. Brockdorff-Rantzau was held in high esteem by the Soviet government and had a good personal relationship with Soviet foreign minister (People's Commissar of Foreign Affairs) Georgy Chicherin.