On September 3, 1971, the parties made a breakthrough in the negotiations. This roundtable focused on preparatory work based on practical provisions that would improve conditions in West Berlin and eliminate irritable barriers. The four-power agreement on Berlin set out that in addition to the Allies` agreement, two German states were recognized under the fundamental treaty (from June 1973) and both countries pledged to respect the sovereignty of both. The treaty provides for exchanges of diplomatic representations and trade, tourism, cultural and communication relations. In September 1973, the two German states joined the United Nations. The regions of Serbia, Montenegro and Romania, which remained independent, have been reduced. Bosnia and Herzegovina was in the austria-Hungary zone of occupation. Russia has retained the mouth of the Danube, in the Caucasus – Kars and Ardahan; Batum has become a free port for trade. As for the Alashkertskaya Valley and the city of Bajazet, Russia has returned them to Turkey. The definitions of the Treaty of Paris of 1856 and the London Convention on the Straits of 1871 remained unchanged. England, which had entered into a secret agreement with the sultan, received Cyprus for its assistance to Turkey. The Nixon administration considered that the resolution of concrete issues that divide Europe was the priority of a successful foreign policy of détente – the easing of hostility or tensions between countries through negotiation rather than confrontation. One of these topics focused on 20 years of disagreement over the ideal solution for Berlin.
The ideal solution for the Berlin question was reunification, but in the face of tensions between all those responsible, it was simply not possible. The four-power agreement on Berlin, also known as the Berlin Agreement or the four-party agreement on Berlin, was concluded on 3 September 1971 by the four allied powers of the war, represented by their ambassadors. The four foreign ministers alec Douglas-Home of the United Kingdom, Andrei Gromyko of the Soviet Union, Maurice Schumann of France and William P. Rogers of the United States signed the agreement and put it into force in Berlin on 3 June 1972.  The agreement was not a treaty and did not require formal ratification. Part I. General Provisions 1. The four governments will work to promote the elimination of tensions and the prevention of complications in the area concerned. (2) Given their obligations under the Charter of the United Nations, the four governments agree that there is no use of force or threat of violence in the region and that disputes can only be resolved through peaceful means. 3. The four governments will respect each other`s individual and common rights and obligations, which remain unchanged.
(4) The four governments agree that, regardless of legal differences of opinion, the situation that has developed in this region and as defined in this agreement and in the other agreements covered in this agreement will not be unilaterally changed. – The Soviet Union agreed that the communication between West and East And East Berlin and the German Democratic Republic and the visitation rights of West Berlin should be improved. In addition, it was agreed that, if the security and status of the city are not involved, the Federal Republic of Germany may represent the Western sectors of Berlin abroad and that international agreements and agreements concluded by the Federal Republic of Germany can be extended to Western sectors.