Finns. Talvisota, Jatkosota & Lapisota, three wars during WW2.
Finnish, German, and Soviet troops at the start of the Continuation War in June/July 1941. The Germans began their assault on 29 June from Petsamo area, and the Finns attacked on 1 July from Suomussalmi and Kuusamo area.
In the interwar period Finland maintained an uneasy neutrality. In 1939-1940 it fought the defensive Finnish-Soviet War (1939-1940). Its territorial losses as a result of that conflict were an outcome foreordained by the demographic reality that just 4 million Finns faced a population of 171 million in the pre-1941 Soviet Union, and that the Red Army was the largest armed force in the world. Finland did not have German support while fighting the Soviets in 1939. Adolf Hitler began to view Finland differently as he prepared to launch Operation BARBAROSSA, starting as early as July 1940.
German arms were delivered to the Finns, transit agreements were signed permitting German troops to move across Finnish territory to and from conquered Norway, and full military staff conversations began in December. Moscow did not know the full extent of Finish-German military coordination, but even its fear of Germany's unabated appetite for ever more territory was finally aroused. Hitler's creeping influence in a country that Joseph Stalin viewed as within his sphere of influence, as previously agreed between Moscow and Berlin, raised anger and fear in the Kremlin. The question of which Great Power would exercise ultimate hegemony over Finland thus became a critical diplomatic issue in the year between the fall of France in June 1940 and the Axis invasion of the Soviet Union in June 1941. Finland joined the Axis attack on the Soviet Union after a strictly operational delay of a few days, but Finland was never a full Axis state in spirit or intent. For the Finns, resumption of active hostilities with the Soviet Union was solely an effort to reverse their loss of 1940, a strictly limited war aim reflected in their term for the conflict: "Continuation War."
The Finnish Army of 1941 was greatly expanded from its dispositions of 1939: it fielded 16 excellent divisions equipped with modern German weapons. Wehrmacht land, air, and naval forces took up attack positions in northern Finland in April-June, 1941. Preparatory to BARBAROSSA, four German divisions were allowed into Lapland to open a high Arctic front. On the opening day of the campaign, June 22, the Finnish Navy occupied the Aland Islands without interference by the Soviet Navy. German troops also attacked out of Lapland toward Murmansk and the Kola Peninsula. Finnish troops opened a southern front in Karelia a few days later. Once the Finns reached their old 1939 boundary they stopped, encouraged to do so by heavy pressure from the United States, but not before Great Britain declared war on Finland in solidarity with the Soviet Union. In that desperate hour for London, any enemy of Hitler was Britain's ally, and any ally of Germany was necessarily Britain's enemy. The Finns did not advance farther during the rest of the war. Trying to take Leningrad and Moscow were German, not Finnish, war aims. Even so, the effort to recover lost territory by swimming with the turn of the geopolitical tide in 1941 engaged the Finns in a long war on what became the northernmost section of the Eastern Front: fighting against the Red Army lasted from June 1941 to September 1944, with more limited fighting against the Germans after that.
Over the course of the naval war, the Finnish Navy lost one monitor, six minesweepers, and 50 merchantmen and coastal patrol ships. Finland lost far more men in land combat, as Hitler's BARBAROSSA operation failed by the end of November 1941. The Red Army counterattacked in the Moscow offensive operation (December 5, 1941-January 7, 1942) and the Rzhev-Viazma strategic operation (January 8-April 20, 1942). The Finnish front thereafter stretched from German positions outside Leningrad, across southern Karelia and along the forest zone of the eastern frontier, to a distant fight by mainly German troops in the high Arctic Circle. The Finns again held back from advancing toward Leningrad, but their presence in southern Karelia completed a three-sided German lock on that starving city throughout the 900-day siege of Leningrad. The Finns also placed restrictions on permitted Wehrmacht operations in their high Arctic territory, including during Operation LACHSFANG. By the end of 1942 the Finns were in the increasingly difficult position of waiting to see which of their vastly more powerful neighbors would win the war along the Eastern Front. They were also influenced by pressure from Washington not to exceed recovery of their national territory, on pain of incurring American displeasure or even a declaration of war to match Britain's.
Germany was clearly losing the war at the start of 1943, a fact brought home to the Finns by German defeats at El Alamein and Stalingrad. The Finns opened secret talks with Moscow in an effort to withdraw from the war by negotiating a limited frontier settlement. But Moscow and Helsinki could not agree on where to draw the border in Karelia, the mutual casus belli in 1939 and again in 1941. The Red Army went over to the permanent offensive all along the Eastern Front in the late summer of 1943, following another great victory at Kursk and follow-on counteroffensives in the north and in Ukraine. Finnish-Soviet talks broke down in February 1944, even as German Army Group North was pushed back from Leningrad to the Panther Line section of the Ostwall. The Red Army attacked the main Finnish position on the Mannerheim Line on June 10, 1944, achieving complete operational surprise. Soviet tanks and mobile infantry broke through the next day. The Finns now discovered how greatly improved in combat performance the Red Army was since the winter of 1939-1940. Soviet forces were far superior in weapons, veteran troops, and proven commanders. General Leonid A. Govorov's Karelian Front took Vyborg within two weeks, a triumph for which he was promoted to "Marshal of the Soviet Union." The Stavka launched the second phase of the "Svir-Petrozavodsk operation," a full-scale invasion of lower Finland, through the southern forests on June 21. At first, Hitler sent German reinforcements to Finland in exchange for agreement that Helsinki would not accept a separate peace with Moscow. But the combat pressure from Karelian Front was relentless, while the Germans were themselves knocked backward 300 miles by the stunning Soviet achievement of Operation BAGRATION in Belorussia. That marked the start of a cascading series of Soviet victories and catastrophic German defeats in the center of the Eastern Front, which left the more northern German and Finnish flank hanging.
Compared to its performance in Finland in 1939-1940, the Red Army's second campaign in Karelia was a superior example of combined arms warfare, or Blitzkrieg. Yet, Moscow did not pursue total war against Finland the way it did against all other Axis states. Stalin was prepared to offer terms to the Finns partly in response to intervention by President Franklin D. Roosevelt and the wider issues of alliance politics that might be adversely affected. Nevertheless, events on the ground had a life of their own. Elements of the powerful Karelian Front crossed the Svir River, forcing the Finnish Army back under great pressure. The Soviets took the provincial capital of Petrozavodsk on June 28. Other Red Army Fronts simultaneously attacked in central and northern Finland, at Salla and Petsamo, where they battered German 20th Mountain Army. That isolated 200,000 Axis troops, left guarding a peripheral position by Hitler, while the center and south of the entire Eastern Front were collapsing for want of men. By August 9, the Red Army achieved all goals set by the Stavka for the summer campaign in the north. Events outside Finland also conduced to lessened Soviet operations. German resistance in Estonia and Latvia collapsed during late July, in tandem with a general military crisis for the Germans attendant on the devastation of Army Group Center in BAGRATION. That defeat signaled to Helsinki that it needed to get out of the war before Finland, too, was wholly overrun.
Mannerheim was brought back to the presidency on August 4, tasked to negotiate an exit from the war. On August 24 the cabinet agreed to seek a ceasefire and armistice with Moscow. Soviet troops stopped advancing five days later. On September 2 the Finns formally severed alliance ties to Germany. A ceasefire was agreed with the Soviets three days after that. Retreating Germans tried to seize the critical Finnish island of Suursaan (or Hogland) in the Gulf of Finland. The attempt was beaten off by Soviets and Finns fighting in tandem against the Germans for the first time.
Finland signed a formal armistice with Moscow on September 19, 1944. The agreement restored the expanded Soviet border of 1940, confirming that Finland had lost the "Continuation War" as well as the earlier Finnish-Soviet War. Helsinki surrendered rights to a Soviet naval base at Petsamo and to a Red Army and VVS air base outside Helsinki. The key to the armistice was that it required Finland to declare war on Germany and the Finnish Army to actively expel all Wehrmacht and SS troops from the country. But Finnish soldiers proved lax about enforcing that clause against men who were comrades-in-arms just days earlier. Instead, the Finnish Army simply watched German troops flee the country. In some cases, the Finns peacefully escorted rather than harried German troops on their way out during the Wehrmacht's BIRKE withdrawal operation (September 3-29, 1944). There was only one serious armed clash during September between Finnish and German troops. More serious clashes between Finns and Germans marked the later Lapland War, fought during the winter of 1944-1945 with the last German troops in the high Arctic. Under great Soviet pressure, Finland formally declared war on Germany on March 3, 1945. The last German troops left the high north a month later.
American support for Finland's independence helped prevent its incorporation into the Soviet Union as another lost tsarist province and kept it outside the quickly forming bloc of Soviet client states. In 1947 a formal peace treaty was signed between Finland and those Allied states with which it had been formally at war. Helsinki permanently surrendered its disputed Karelian territory to the Soviet Union. It was thereafter compelled to adopt the Soviet foreign policy line throughout the Cold War, but it was not forced to host Soviet armed forces beyond a single base at Porkkala. That base was later exchanged for a Soviet lease on Hangö, which was in turn given up by Moscow in 1955. Unlike Czechs, Poles, or Rumanians, the Finns did not have to adopt Soviet domestic policies and were never ruled by a puppet Communist Party. Similar Cold War arrangements in which foreign policy obeisance to a Great Power was combined with domestic independence became known internationally as "Finlandization."