Soviet-German Talks. 21–28 September, 1939
During their invasion of Poland, German troops crossed into the Soviet sphere of interests defined by the secret protocol to the Soviet-German Treaty of Non-Aggression. Striving to protect its national and ethnic interests, the Soviet government urged the Germans to return as quickly as possible behind the line set down in the agreement concluded in Moscow on August 23, 1939.
After protracted talks, representatives of the Soviet and German military commands signed on September 21, 1939, a protocol about the withdrawal of Wehrmacht divisions to the west and the transfer of the occupied territory to the Red Army. A Soviet-German communiqué about a line of demarcation between the Wehrmacht and the Red Army passing through former Polish territory appeared in the press on September 23, 1939.
On September 27, 1939, German Foreign Minister J. von Ribbentrop came to Moscow. The same day, the German and Soviet foreign ministers launched a round of talks that led to the signature on September 28, 1939, of the German-Soviet Boundary and Friendship Treaty and a series of supplementary protocols (some of which remained secret).
The treaty defined the border between Germany and the USSR as mostly running along the rivers San and Bug, which basically coincided with the so-called Curzon Line that had been proposed as far back as 1919 by Great Britain and other Entente powers as a fair border between Poland and the Soviet republics. At the same time, the secret supplementary protocol, which modified the Soviet-German agreement of August 23, 1939, ceded Lithuania to the USSR and the Lublin Voivodeship and part of the Warsaw Voivodeship to Germany. An agreement was also reached on the exchange of population between the spheres of interest of Germany and the USSR.
Despite all the diplomatic politesse that accompanied the talks and the signature of international treaties, the Soviet-German ‘friendship’ existed in name only.
The USSR took a neutral stance in the war between Nazi Germany, on the one side, and France and Great Britain, on the other.