Editing Mannerheim Line (section)

===Background===
[[File:Mannerheim3.jpg|thumb| [[Carl Gustaf Emil Mannerheim]] in 1937]]

After the [[October Revolution]] in the [[Russian Empire]], the Finns [[Finland's Declaration of Independence|declared independence]] in 1917. Although the [[Russian Soviet Federative Socialist Republic|Soviet Union]] recognized Finland's independence, the Finns did not trust their sincerity. The relationship between the two countries deteriorated, with Soviet Russia supporting the [[Red Guards (Finland)|Red Guard]] during the [[Finnish Civil War]] in 1918. After the victory of the [[White Guard (Finland)|White Guard]], a group of Finnish communists fled to Soviet Russia and established the [[Communist Party of Finland]].<ref name="UittoGeust1">[[#UittoGeust2006|Geust & Uitto 2006]], page 9</ref>

The situation was considered dangerous for a new nation like Finland, especially as the capital of the new communist revolution was nearby [[Petrograd]], (now [[Saint Petersburg]]). Furthermore, before the [[Treaty of Tartu (Russian–Finnish)|Treaty of Tartu]] in 1920, the border area was restless. The former general of Imperial Russia, C.G.E. Mannerheim, strongly opposed the [[Bolshevik]]s (Communists). Construction work on the Karelian Isthmus had already begun when the Bolsheviks won the Russian Civil War in 1922.<ref name="UittoGeust1" /> The line was constructed in two phases: In 1920–1924 and 1932–1939.