On this day in military history…
After the fall of Warsaw on September 28, 1939, the fate of Poland was formally sealed by an agreement between Nazi Germany and the Soviet Union. This agreement, known as the German–Soviet Boundary and Friendship Treaty, was a continuation and modification of the earlier Molotov–Ribbentrop Pact, which had secretly divided Eastern Europe into spheres of influence prior to the outbreak of World War II. While the initial invasion of Poland began on September 1 with German forces advancing from the west, the Soviet Union entered from the east on September 17, exploiting the collapse of Polish defenses and the prior arrangements made in secret with Germany.
The swift conquest of Poland forced the two powers to negotiate a more precise and formal partition of the territory. On September 28, as German troops solidified their control over central and western Poland and Soviet forces held the east, representatives of both governments met in Moscow to finalize the division. Germany was represented by Foreign Minister Joachim von Ribbentrop, while Vyacheslav Molotov, the Soviet Foreign Minister, acted on behalf of the USSR. The discussions were overseen personally by Joseph Stalin, who played a decisive role in determining the new borders.
The treaty was officially signed in Moscow and included several key provisions. It redrew the boundary between German and Soviet occupied zones, giving Germany control of Warsaw and much of central Poland, while the Soviets were granted authority over the eastern territories, including areas inhabited by Ukrainians, Belarusians, and Lithuanians. Lithuania, originally assigned to the German sphere in the August agreement, was now shifted to the Soviet side, with the exception of a small region around Suwałki.
Beyond territorial adjustments, the treaty also included secret protocols concerning the fate of the Polish population. Both sides agreed to suppress any signs of Polish nationalism or resistance within their zones. There were provisions for population transfers as well, allowing ethnic Germans living in Soviet-occupied regions to be relocated westward, while Poles, Jews, and other groups considered undesirable by the Nazis were often deported or persecuted. This coordination later evolved into direct collaboration between German and Soviet security services, including the Gestapo and the NKVD.
Though the official treaty bore the date of September 28, parts of the agreement, particularly the secret protocols, were signed the following day but backdated for uniformity. Some documents were finalized as late as October 4, when Molotov signed further clarifications with the German ambassador in Moscow, Friedrich-Werner von der Schulenburg.
The German–Soviet Boundary and Friendship Treaty marked the formal end of Poland as an independent state in 1939. The country was erased from the map and partitioned between two totalitarian regimes. Though hostilities between the signatories would erupt less than two years later, the short-lived cooperation between Nazi Germany and the Soviet Union in the destruction of Poland remains one of the most cynical and consequential episodes in the early months of the Second World War.
