Nazi Germany and the USSR concluded a major trade-and-credit arrangement that expanded economic ties and set the stage for a broader political accommodation days later.
Germany and the Soviet Union signed a 10-year non-aggression pact. A secret protocol divided much of Eastern Europe into German and Soviet spheres of influence, fundamentally reshaping their diplomacy and enabling coordinated expansion.
Germany’s invasion of Poland triggered the European war and operationalized the pact’s political framework by setting up the partition of Poland envisioned in the secret protocol.
The USSR entered Poland from the east, citing the collapse of the Polish state; in practice, the move aligned with the secret protocol’s partition plans and completed the two-front destruction of Poland.
Germany and the USSR signed a follow-up treaty fixing the demarcation line in occupied Poland and revising sphere arrangements (including Lithuania) via additional secret protocols, formalizing the results of their joint conquest.
Lithuania accepted Soviet bases and troop deployments in exchange for parts of the Vilnius region, deepening Soviet leverage in the Baltic area anticipated in 1939 diplomacy.
After failed demands to move the border and secure bases, the USSR attacked Finland. The conflict unfolded in the broader diplomatic context created by the 1939 German–Soviet arrangement.
Germany and the USSR signed a large trade pact exchanging Soviet raw materials for German machinery and technology, tightening economic interdependence during the first year of the pact.
In June 1940, the USSR moved to occupy Estonia, Latvia, and Lithuania—building on the 1939 mutual-assistance pacts and consolidating control in the Soviet sphere established by earlier German–Soviet agreements.
Following an ultimatum to Romania, Soviet forces occupied Bessarabia and Northern Bukovina, advancing claims foreshadowed in 1939 secret diplomacy and prompting German–Soviet coordination concerns.
Molotov met German leaders in Berlin amid discussions over a possible broader alignment and competing ambitions in Eastern Europe and the Balkans—talks that revealed growing strain beneath ongoing cooperation.
Germany and the USSR signed a broad settlement covering border and property issues and extending trade provisions; secret arrangements addressed disputes related to Lithuania and other territorial/economic frictions.
Germany launched its invasion of the Soviet Union, unilaterally ending the core premise of the 1939 non-aggression pact and transforming German–Soviet diplomacy into total war.
In response to Germany’s invasion, Britain and the USSR agreed to cooperate against Nazi Germany and not to conclude a separate peace—cementing the diplomatic reversal after the pact’s collapse.
German-Soviet Diplomacy, the Molotov–Ribbentrop Pact and its Collapse (1939–1941)
