Finland was invaded by the USSR in 1940. Although outnumbered a million Soviet troops against 200,000 Finnish troops in just 9 divisions, the Soviets were held back by the Fins, due in part to the extensive Finnish railroad system and ski troops, as well as the low quality and preparedness of Soviet forces. After a few months, however, Finland had to sue for peace in return for losing their provence of Karelia. The Finns allied with Germany for Operation Barbarossa, collaborating with German divisions in Norway. However, they refused to push far into the USSR once they retook their lost land. After the war, Finland was one of the few countries to escape Communist rule.