Finland and the Soviet Union sign the Moscow Peace Treaty

Stalin’s report at the congress celebrated the Soviet Union’s industrial and military development while presenting international rivalry as a long-term threat. The gathering followed the peak of the...

The public non-aggression treaty included secret protocols dividing spheres of influence in Eastern Europe. It gave both governments room to pursue expansion and exposed smaller states to decisions...

After Germany invaded Poland, Soviet forces crossed the eastern border under the pact’s secret arrangements. Polish territory was divided between two occupying powers; residents faced arrests,...

Soviet forces crossed the Finnish border after failed negotiations over security near Leningrad. The war exposed the costs of Stalin’s coercive diplomacy and the Red Army’s weaknesses after the...

The Soviet Politburo approved a proposal to execute thousands of Polish officers and prisoners held by the NKVD. The killings at Katyn and other sites were part of a broader effort to eliminate Polish...

Moscow demanded a new government and the entry of additional Soviet troops into Lithuania. Soviet pressure was followed by occupation and annexation, extinguishing Lithuanian independence. The episode...

Elections held under occupation offered voters a single approved list and were followed by petitions for incorporation into the Soviet Union. These procedures supplied a veneer of popular consent...

The USSR’s Supreme Soviet accepted Lithuania as a union republic after occupation and controlled elections. Soviet rule brought land nationalization, arrests, deportations, and the dismantling of...

An agent linked to Soviet security killed Trotsky, who died the next day. The assassination removed Stalin’s most prominent revolutionary rival abroad and extended Soviet political violence beyond its...

The invasion opened a war of annihilation across Soviet territory. Stalin’s government had failed to prepare effectively despite warnings; civilians and soldiers endured occupation, mass killing,...