vernment launched a planned economy, industrialisation of the largely rural country, and collectivization of its agriculture. During this period of rapid economical and social changes, millions of people were sent to penal labor camps, including many political convicts who opposed Stalin's rule, and millions were deported and exiled to remote areas of the Soviet Union. The transitional disorganisation of the country's agriculture, combined with the harsh state policies and a drought, led to the Soviet famine of 1932–1933. However, though with a heavy price, the Soviet Union was transformed from a largely agrarian economy to a major industrial powerhouse in a short span of time.
The Appeasement policy of Great Britain and France towards Adolf Hitler's annexations of Ruhr, Austria and finally of Czechoslovakia enlarged the might of Nazi Germany and put a threat of war to the Soviet Union. Around the same time the German Reich allied with the Empire of Japan, a rival of the USSR in the Far East and an open enemy in the Soviet–Japanese Border Wars in 1938–39.
In August 1939, after another failure of attempts to establish a counter-Nazism alliance with Britain and France, and after Western powers had engaged in the policy of Appeasement with Nazi Germany, the Soviet government finally agreed to establish peaceful relations by concluding the Molotov-Ribbentrop Pact, pledging non-aggression between the two countries and dividing their spheres of influence in Eastern Europe. While Hitler conquered Poland, France and other countries acting on single front at the start of World War II, the USSR was able to build up its military and regain some of the former territories of the Russian Empire during the Soviet invasion of Poland and the Winter War.
On 22 June 1941, Nazi Germany broke the non-aggression treaty and invaded the Soviet Union with the largest and most powerful invasion force in human history, opening the largest theater of World War II
