Leading up to Winter War
In the autumn of 1939, the Soviet Union demanded territorial cessions from Finland. Negotiations were also opened with Estonia, Latvia and Lithuania. They agreed to give the Red Army bases on their territory and to allow Soviet troops into the country. Finland chose otherwise. The negotiations ended without results on 9th of November 1939.
Soviet demands
The Soviet Union quickly began to exploit the Molotov-Ribbentrop Pact. The Baltic countries were pressured to hand over bases to the Red Army. Finland's turn to be invited to the negotiations came on 5th October 1939.
The government decided to send counsellor of state J. K. Paasikivi to Moscow. The Soviet Union's demands were the transfer of the border on the Karelian Isthmus to the Koiviston-Lipola Plain, the surrender of the islands in the Gulf of Finland and the Kalastajasaarento in Petsamo. In addition, the Soviet Union wanted a base in Hanko. The Finnish government could not agree to the cessions.
Paasikivi was accompanied by the chairman of the Social Democratic Party, Väinö Tanner, on another negotiating mission to Moscow. On 23rd of October 1939, they submitted a counter-proposal to the Finnish government, which would cede the outer islands of the Gulf of Finland and the so-called Kuokkala Bend in the Karelian Isthmus to the Soviet Union in return for compensation. The cession of the Kuokkala Bend would have moved the border 13 kilometres further west. In Finland's counter-proposal, the Government rejected the demand to lease Hanko. The Soviet Union did not accept Finland's counter-proposal and the negotiations broke off on 9th of November 1939 without success.
Extra refresher excercises
During the Moscow negotiations in October of 1939, Finland carried out extra refresher excercises, which in practice meant a mobilisation. The choice of words was intended to disguise the mobilisation and obscure the impression of an imminent threat of war.
The extra exercises were carried out in two phases. In the first phase, starting on 9th of October, a delaying action force and a few divisions in the border areas were set up. In the second phase, starting on 14th of October, the rest of the field army was formed and concentrated.
For the men, the exercises, which lasted more than a month, gave the opportunity to familiarise themselves with their wartime unit, their tasks and the operational terrain. The exercise also included the fortifying of defensive positions.
The staged shots of Mainila
Finland's negative position in the negotiations came as an obvious surprise to Stalin. After the negotiations stopped, the Soviet Union began to consistently prepare public opinion against Finland. Mass rallies were held in Soviet factories against 'Finnish warmongers and vagrants' and newspapers smeared Finland. Dictators were and often are masters of the art of stagecraft - before his attack, Hitler had framed the Poles for an attack on a German border post.
Soviet union framed the shots fired at Mainila on 26th of November 1939 to get an excuse to attack Finland. Finnish artillery allegedly fired on Soviet troops in the village of Mainila, killing or wounding 13 men. On 28th of November 1939, the Soviet government terminated the non-aggression pact between Finland and the Soviet Union. Finnish troops were alleged to have threatened the security of Leningrad.