Continuation War
The Continuation War, also known as the Second Soviet–Finnish War, was a conflict fought by Finland and Nazi Germany against the Soviet Union during World War II. It began with a Finnish declaration of war on 25 June 1941 and ended on 19 September 1944 with the Moscow Armistice. The Soviet Union and Finland had previously fought the Winter War from 1939 to 1940, which ended with the Soviet failure to conquer Finland and the Moscow Peace Treaty. Numerous reasons have been proposed for the Finnish decision to invade, with regaining territory lost during the Winter War regarded as the most common. Other justifications for the conflict include Finnish President Risto Ryti's vision of a Greater Finland and Commander-in-Chief Carl Gustaf Emil Mannerheim's desire to annex East Karelia.
On 22 June 1941, the Axis invaded the Soviet Union. Three days later, the Soviet Union conducted an air raid on Finnish cities which prompted Finland to declare war and allow German troops in Finland to begin offensive warfare. By September 1941, Finland had regained its post–Winter War concessions to the Soviet Union in Karelia. The Finnish Army continued its offensive past the 1939 border during the invasion of East Karelia and halted it only around from the centre of Leningrad. It participated in besieging the city by cutting the northern supply routes and by digging in until 1944. In Lapland, joint German–Finnish forces failed to capture Murmansk or cut the Kirov Railway. The Soviet Vyborg–Petrozavodsk offensive in June and August 1944 drove the Finns from most of the territories that they had gained during the war, but the Finnish Army halted the offensive in August 1944.
Hostilities between Finland and the USSR ceased in September 1944 with the signing of the Moscow Armistice in which Finland restored its borders per the 1940 Moscow Peace Treaty and additionally ceded Petsamo and leased the Porkkala Peninsula to the Soviets. Furthermore, Finland was required to pay war reparations to the Soviet Union, accept partial responsibility for the war, and acknowledge that it had been a German ally. Finland was also required by the agreement to expel German troops from Finnish territory, which led to the Lapland War between Finland and Germany.
Background
Winter War
On 23 August 1939, the Soviet Union and Germany signed the Molotov–Ribbentrop Pact in which both parties agreed to divide the independent countries of Finland, Estonia, Latvia, Lithuania, Poland, and Romania into spheres of interest, with Finland falling within the Soviet sphere. One week later, Germany invaded Poland, leading to the United Kingdom and France declaring war on Germany. The Soviet Union invaded eastern Poland on 17 September. The Soviet government turned its attention to the Baltic states of Estonia, Latvia, and Lithuania, demanding that they allow Soviet military bases to be established and troops stationed on their soil. The Baltic governments acquiesced to these demands and signed agreements in September and October.In October 1939, the Soviet Union attempted to negotiate with Finland to cede Finnish territory on the Karelian Isthmus and the islands of the Gulf of Finland, and to establish a Soviet military base near the Finnish capital of Helsinki. The Finnish government refused, and the Red Army invaded Finland on 30 November 1939. The same day, Field Marshal C. G. E. Mannerheim, who was chairman of Finland's Defence Council at the time, assumed the position of Commander-in-Chief of the Finnish Defence Forces. The USSR was expelled from the League of Nations and was condemned by the international community for the illegal attack. Foreign support for Finland was promised, but very little actual help materialised, except from Sweden. The Moscow Peace Treaty concluded the 105-day Winter War on 13 March 1940 and started the Interim Peace. By the terms of the treaty, Finland ceded 9% of its national territory and 13% of its economic capacity to the Soviet Union. Some 420,000 evacuees were resettled from the ceded territories. Finland avoided total conquest of the country by the Soviet Union and retained its sovereignty.
Prior to the war, Finnish foreign policy had been based on multilateral guarantees of support from the League of Nations and Nordic countries, but this policy was considered a failure. After the war, Finnish public opinion favored the reconquest of territory ceded to the Soviet Union. The government declared national defence to be its first priority, and military expenditure rose to nearly half of public spending. Finland both received donations and purchased war materiel during and immediately after the Winter War. Likewise, the Finnish leadership wanted to preserve the spirit of unanimity that was felt throughout the country during the Winter War. The divisive White Guard tradition of the Finnish Civil War's 16 May victory-day celebration was therefore discontinued.
The Soviet Union had received the Hanko Naval Base, on Finland's southern coast near the capital Helsinki, where it deployed over 30,000 Soviet military personnel. Relations between Finland and the Soviet Union remained strained after the signing of the one-sided peace treaty, and there were disputes regarding the implementation of the treaty. Finland sought security against further territorial depredations by the USSR and proposed mutual defence agreements with Norway and Sweden, but these initiatives were quashed by Moscow.
German and Soviet expansion in Europe
After the Winter War, Germany was viewed with distrust by the Finnish, as it was considered an ally of the Soviet Union. Nonetheless, the Finnish government sought to restore diplomatic relations with Germany, but also continued its Western-orientated policy and negotiated a war trade agreement with the United Kingdom. The agreement was renounced after the German invasion of Denmark and Norway on 9 April 1940 resulted in the UK cutting all trade and traffic communications with the Nordic countries. With the fall of France, a Western orientation was no longer considered a viable option in Finnish foreign policy. On 15 and 16 June, the Soviet Union occupied the Baltic states almost without any resistance and Soviet puppet regimes were installed. Within two months Estonia, Latvia and Lithuania were incorporated into the USSR and by mid–1940, the two remaining northern democracies, Finland and Sweden, were encircled by the hostile states of Germany and the Soviet Union.On 23 June, shortly after the Soviet occupation of the Baltic states began, Soviet Foreign Minister Vyacheslav Molotov contacted the Finnish government to demand that a mining licence be issued to the Soviet Union for the nickel mines in Petsamo or, alternatively, permission for the establishment of a joint Soviet-Finnish company to operate there. A licence to mine the deposit had already been granted to a British-Canadian company and so the demand was rejected by Finland. The following month, the Soviets demanded that Finland destroy the fortifications on the Åland Islands and to grant the Soviets the right to use Finnish railways to transport Soviet troops to the newly acquired Soviet base at Hanko. The Finns very reluctantly agreed to those demands. On 24 July, Molotov accused the Finnish government of persecuting the communist Finland–Soviet Union Peace and Friendship Society and soon afterward publicly declared support for the group. The society organised demonstrations in Finland, some of which turned into riots.
Russian-language sources from the post-Soviet era, such as the study Stalin's Missed Chance, maintain that Soviet policies leading up to the Continuation War were best explained as defensive measures by offensive means. The Soviet division of occupied Poland with Germany, the Soviet occupation of the Baltic states and the Soviet invasion of Finland during the Winter War are described as elements in the Soviet construction of a security zone or buffer region from the perceived threat from the capitalist powers of Western Europe. Other post-Soviet Russian-language sources consider establishment of Soviet satellite states in the Warsaw Pact countries and the Finno-Soviet Treaty of 1948 as the culmination of the Soviet defence plan. Western historians, such as Norman Davies and John Lukacs, dispute this view and describe pre-war Soviet policy as an attempt to stay out of the war and regain the land lost due to the Treaty of Brest-Litovsk after the fall of the Russian Empire.
Relations between Finland, Germany and Soviet Union
On 31 July 1940, Adolf Hitler gave the order to plan an assault on the Soviet Union, meaning Germany had to reassess its position regarding both Finland and Romania. Until then, Germany had rejected Finnish requests to purchase arms, but with the prospect of an invasion of Russia, that policy was reversed, and in August, the secret sale of weapons to Finland was permitted. Military authorities signed an agreement on 12 September, and an official exchange of diplomatic notes was sent on 22 September. Meanwhile, German troops were allowed to transit through Sweden and Finland. This change in policy meant Germany had effectively redrawn the border of the German and Soviet spheres of influence, in violation of the Molotov–Ribbentrop Pact.In response to that new situation, Molotov visited Berlin on 12–13 November 1940. He requested for Germany to withdraw its troops from Finland and to stop enabling Finnish anti-Soviet sentiments. He also reminded the Germans of the 1939 pact. Hitler inquired how the Soviets planned to settle the "Finnish question" to which Molotov responded that it would mirror the events in Bessarabia and the Baltic states. Hitler rejected that course of action. During the Finnish presidential election in December 1940, Risto Ryti was elected to be president largely due to interference by Molotov in Ryti's favour since he had signed the Moscow Peace Treaty as prime minister.
On 18 December 1940, Hitler officially approved Operation Barbarossa, paving the way for the German invasion of the Soviet Union, in which he expected both Finland and Romania to participate. Meanwhile, Finnish Major General Paavo Talvela met with German Colonel General Franz Halder and Reich Marshal Hermann Göring in Berlin, the first time that the Germans had advised the Finnish government, in carefully-couched diplomatic terms, that they were preparing for war with the Soviet Union. Outlines of the actual plan were revealed in January 1941 and regular contact between Finnish and German military leaders began in February. Additionally in January 1941, Moscow again demanded Finland relinquish control of the Petsamo mining area to the Soviets, but Finland, emboldened by a rebuilt defence force and German support, rejected the proposition.
In the late spring of 1941, the USSR made a number of goodwill gestures to prevent Finland from completely falling under German influence. Ambassador was replaced with the more conciliatory and passive. Furthermore, the Soviet government announced that it no longer opposed a rapprochement between Finland and Sweden. Those conciliatory measures, however, did not have any effect on Finnish policy. Finland wished to re-enter the war mainly because of the Soviet invasion of Finland during the Winter War, which the League of Nations and Nordic neutrality had failed to prevent due to lack of outside support. Finland primarily aimed to reverse its territorial losses from the 1940 Moscow Peace Treaty and, depending on the success of the German invasion of the Soviet Union, to possibly expand its borders, especially into East Karelia. Some right-wing groups, such as the Academic Karelia Society, supported a Greater Finland ideology. This ideology of a Greater Finland mostly composed of Soviet territories was augmented by anti-Russian sentiments.