POLISH-SOVIET WAR
YEARS: 1919-1920 | DEATHS: 50000
After the First World War, Poland regained independence lost with the Third Partiton of Poland in 1795. After 123 years of annexation Second Polish Republic was proclaimed in 1918.
Polish leader Józef Piłsudski envisioned a new federation (sometimes called Federation of Międzymorze) which would be composed of Poland, Lithuania and western Ukraine (centered at Kyiv), forming a Polish-led East European confederation as a counterweight to Russia. This new country was to have similar borders to the former Polish-Lithuanian Commonwealth from 16th—18th century.
At the same time Russia was transforming into the Soviet Union, through the Russian Revolutions and Russian Civil War that begun in 1917.
Lenin, leader of the new communist government of Russia, saw Poland as the bridge that would have to be crossed in order to help the communists fractions in Germany and Western Europe, according to the plan that would bring the worldwide domination of communism, as predicted by Karl Marx. When the German Revolution begun in 1918 Soviets decided it was time to start expanding their influence westwards.
SOURCE(S):
Wikipedia, published under the GNU FDL