2019 is the 80th anniversary of the Winter War (1939–1940) between the Soviet Union and Finland. The small nation of Finland succeeded in defending its territories against a far larger army of the Soviet Union.
On the 30th of November 1939 Soviet troops attacked Finland in order to seize the areas which according to the Molotov-Ribbentrop pact belonged to the Soviet Union.
Against all odds, Finland, a weak, sparsely populated and diplomatically isolated nation, succeeded in causing staggering losses on a far more potent aggressor by skillfully utilizing the wintery conditions.
More @ War History Online