Question: Which country aided Finland in Operation Stella Polaris against the Soviet Union?

Context articles: Continuation War
Soviet deportations from Lithuania
German–Soviet Axis talks
1991 Soviet coup d'état attempt
Operation Stella Polaris
Finnish presidential election, 1940
Moscow Peace Treaty
C-byrån
Lapland War
Soviet–Finnish Non-Aggression Pact

The Continuation War (Finnish: "jatkosota" ; Swedish: "fortsättningskriget" ; 25 June 1941 – 19 September 1944) consisted of hostilities between Finland and the Soviet Union from 1941 to 1944.
 The Continuation War began 15 months after the end of the Winter War, which was also fought between Finland and the Soviet Union.
 In the Soviet Union, the war was considered part of the Great Patriotic War.
 Germany regarded its operations in the region as part of its overall war efforts on the Eastern Front, and it provided Finland with critical material support and military cooperation.
Soviet deportations from Lithuania were a series of 35 mass deportations carried out in Lithuania, a country that was occupied as a constituent socialist republic of the Soviet Union, in 1941 and 1945–1952.
 At least 130,000 people, 70% of them women and children, were forcibly transported to labor camps and other forced settlements in remote parts of the Soviet Union, particularly in the Irkutsk Oblast and Krasnoyarsk Krai.
 Among the deportees were about 4,500 Poles.
 These deportations do not include Lithuanian partisans or political prisoners (approximately 150,000 people) deported to Gulags (prison camps).
 Deportations of the civilians served a double purpose: repressing resistance to Sovietization policies in Lithuania and providing free labor in sparsely inhabited areas of the Soviet Union.
 Approximately 28,000 of Lithuanian deportees died in exile due to poor living conditions.
 After Stalin's death in 1953, the deportees were slowly and gradually released.
 The last deportees were released only in 1963.
 Some 60,000 managed to return to Lithuania, while 30,000 were prohibited from settling back in their homeland.
 Similar deportations took place in Latvia, Estonia, and other parts of the Soviet Union (see Soviet deportations from Estonia and population transfer in the Soviet Union).
 Lithuania observes the annual Mourning and Hope Day on June 14 in memory of those deported.
In October and November 1940, German–Soviet Axis talks occurred concerning the Soviet Union's potential entry as a fourth Axis Power in World War II.
 The negotiations, which occurred during the era of the Molotov–Ribbentrop Pact, included a two-day Berlin conference between Soviet Foreign Minister Vyacheslav Molotov, Adolf Hitler and German Foreign Minister Joachim von Ribbentrop, followed by both countries trading written proposed agreements.
 After two days of negotiations from 12 to 14 November 1940, Germany presented the Soviets with a draft written Axis pact agreement defining the world spheres of influence of the four proposed Axis powers (Japan, Germany, Soviet Union, Italy).
 Hitler, Ribbentrop and Molotov tried to set German and Soviet spheres of influence; Hitler encouraged Molotov to look south to Iran and eventually India while preserving German access to Finland's resources, and to remove Soviet influence in the Balkans.
 Molotov remained firm, seeking to remove German troops from Finland and gain a warm water port in the Balkans.
 Soviet foreign policy calculations were predicated by the idea that the war would be a long - term struggle and therefore German claims that Britain would be defeated swiftly were treated with scepticism.
 In addition Stalin sought to remain influential in Bulgaria and Yugoslavia.
 These factors resulted in Molotov taking a firm line.
 According to a Columbia University academical source, on 25 November 1940, the Soviets presented a Stalin-drafted written counterproposal where they would accept the four power pact, but it included Soviet rights to Bulgaria and a world sphere of influence centered on the area around modern Iraq and Iran.
 Germany did not respond, leaving the negotiations unresolved.
 Regarding the counterproposal, Hitler remarked to his top military chiefs that Stalin "demands more and more", "he's a cold-blooded blackmailer" and that "a German victory has become unbearable for Russia" so that "she must be brought to her knees as soon as possible."
 Germany broke the Molotov-Ribbentrop Pact in June 1941 by invading the Soviet Union.
The 1991 Soviet coup d'état attempt, also known as the August Coup (Russian: Августовский путч , "Avgustovsky Putch" "August Putsch"), was an attempt by members of the Soviet Union's government to take control of the country from Soviet President and General Secretary Mikhail Gorbachev.
 The coup leaders were hard-line members of the Communist Party of the Soviet Union (CPSU) who were opposed to Gorbachev's reform program and the new union treaty that he had negotiated which decentralised much of the central government's power to the republics.
 They were opposed, mainly in Moscow, by a short but effective campaign of civil resistance led by Russian president Boris Yeltsin, who had been both an ally and critic of Gorbachev.
 Although the coup collapsed in only two days and Gorbachev returned to government, the event destabilised the Soviet Union and is widely considered to have contributed to both the demise of the CPSU and the dissolution of the Soviet Union.
Operation Stella Polaris was the cover name for activity in which Finnish signals intelligence records, equipment and personnel were transported into Sweden after the ending of the Continuation War in 1944 so that the signals intelligence activities could continue in Sweden and the equipment would not end up in the hands of the Soviet Union.
 The threat of Soviet occupation was considered too likely and an operation was formed to support guerrilla warfare in Finland after occupation.
 The operation had its base in the small fishing village of Nämpnäs in Närpes, Ostrobothnia, where the archives were shipped to the Swedish ports.
 The leaders of the operation was Colonel Aladár Paasonen, chief of the Finnish military intelligence, and Colonel Reino Hallamaa, head of the Finnish signals intelligence section.
Early and indirect presidential elections were held in Finland in 1940 after President Kyösti Kallio resigned on 27 November following a stroke on 27 August.
 The 1937 electoral college was recalled and elected Prime Minister Risto Ryti, who received 288 of the 300 votes.
 Most other Finnish politicians considered Ryti a principled, unselfish, intelligent and patriotic man, who could lead Finland effectively enough during World War II.
 His leadership qualities had been tested already during the Winter War (November 1939-March 1940).
 Also the outgoing President Kallio considered him the best available presidential candidate.
 In early December 1940, the Soviet Foreign Minister, Vyacheslav Molotov, interfered with the Finnish presidential elections by claiming to the Finnish Ambassador to the Soviet Union, J.K. Paasikivi, that if potential presidential candidates such as Marshal Mannerheim, former President Svinhufvud or former Prime Minister Kivimäki were elected President, the Soviet government would consider Finland unwilling to fulfill its peace treaty with the Soviet Union.
 Due to the lingering threat of another war and the Karelian refugees' dispersal throughout Finland, regular presidential elections were cancelled, and instead the 1937 presidential electors were summoned to elect the President.
 Under these tense political circumstances, Ryti had no problem winning these exceptional presidential elections by a landslide (see, for example, Antti Laine, "Finland At War" (Suomi sodassa), pgs.
 705-707 in Seppo Zetterberg et al., eds., A Small Giant of the Finnish History / Suomen historian pikkujättiläinen.
 Helsinki: WSOY, 2003; Pentti Virrankoski, A History of Finland / Suomen historia, volumes 1&2.
 Helsinki: Finnish Literature Society (Suomalaisen Kirjallisuuden Seura), 2009, pg.
 898).
The Moscow Peace Treaty was signed by Finland and the Soviet Union on 12 March 1940, and the ratifications were exchanged on 21 March.
 It marked the end of the 105-day Winter War.
 Finland had to cede border areas to the Soviet Union.
 The treaty was signed by Vyacheslav Molotov, Andrey Zhdanov and Aleksandr Vasilevsky for Soviet Union, and Risto Ryti, Juho Kusti Paasikivi, Rudolf Walden and Väinö Voionmaa for Finland.
C-byrån ("C bureau") was a Swedish secret intelligence agency established in 1939, sorting under the Swedish Armed Forces.
 It was led by Major Carl Petersén.
 During World War II C-byrån organized operations in the German-occupied Norway and Operation Stella Polaris in Finland.
The Lapland War (Finnish: "Lapin sota" ; Swedish: "Lapplandskriget" ; German: "Lapplandkrieg" ) was fought between Finland and Germany from September 1944 to April 1945 in Finland's northernmost Lapland Province.
 For the Finns, this was a separate conflict, much like the Continuation War.
 From a German perspective, the retreat through Lapland was part of the Second World War as part of their two campaigns to evacuate northern Finland and northern Norway: Operation Birke and Operation Nordlicht.
 The Finnish Army was required to demobilise their forces while at the same time fighting to force the German Army to leave Finland.
 German forces retreated to Norway, and Finland managed to uphold its obligations under the Moscow Armistice, although it remained formally at war with the Soviet Union, the United Kingdom and the British Dominions until the formal conclusion of the Continuation War was ratified by the 1947 Paris Peace Treaty.
The Soviet–Finnish Non-Aggression Pact was a non-aggression treaty signed in 1932 by representatives of Finland and the Soviet Union.
 The pact was unilaterally renounced by the Soviet Union in 1939, after it had committed the deception operation Shelling of Mainila, where it shelled its own village and claimed Finland to be responsible.