Foreign support
World opinion at large supported the Finnish cause. The World War hadn't really begun yet, for the time being the Winter War was the only real fight going on, on which the world's interest was focused. The Soviet aggression was generally deemed totally unjustified. Various foreign organizations sent material aid, such as medical supplies. Finnish immigrants in the United States and Canada returned home, and many volunteers travelled to Finland (one of them actor-to-be Christopher Lee) to join Finland's forces: 1,010 Danes, 695 Norwegians, 372 Ingrians, 346 Finnish expats, and 210 volunteers of other nationalities made it to Finland before the war was over. Foreign correspondents in Helsinki wrote, and even greatly exaggerated, reports of supposed Finnish ingenuity and successes in combat.

All empty villages and houses were burnt down when possible. Aim was to slow down enemy´s advance and to make their life as miserable as possible. A village on fire somewhere in Karelian Isthmus.
Sweden, which had declared herself to be a non-belligerent rather than a neutral country (as in the war between Nazi Germany and the Western Powers) contributed with military supplies, cash, credits, humanitarian aid and some 8,700 Swedish volunteers prepared to die for Finland. Maybe most significant was the Swedish Voluntary Air Force, in action from January 7, with 12 fighters, 5 bombers, and 8 other planes, amounting to a third of the Swedish Air Force of that time. Volunteer pilots and mechanics were drawn from the ranks. The renowned aviator Count Carl Gustav von Rosen, related to Hermann Göring, volunteered independently. There was also a volunteering work force, of about 900 workers and engineers.
The Swedish Volunteer Corps with 8,402 men in Finland, and with the only common volunteers who had finished training before the war ended, started to relieve five Finnish battalions at Märkäjärvi in mid-February. Together with three remaining Finnish battalions, the corps faced two Soviet divisions and were preparing for an attack by mid-March, that was inhibited by the peace. 33 men died in action, among them the commander of the first relieving unit, Leutenant Colonel Magnus Dyrssen.
The Swedish volunteers remain a focus of dissonance between Swedes and Finns. The domestic debate in Finland had in the years immediately before the war given common Finns hope of considerably more support from Sweden, notably large regular troops, that could have had a significant impact on the outcome of the war or possibly made the Russians to never attack. As such a more substantial support was expected, Finnish evaluation of gifts, credits and volunteers from Sweden tend to be made on the foundation of deep and bitter disappointment.
Franco-British plans for a Scandinavian theatre
Already within a month, the Soviet leadership began to consider abandoning the operation, but Finland's government was reached by a preliminary peace offer (via Sweden's government) first in the end of January. Until then, Finland had factually fought for its existence. When credible rumours reached the governments in Paris and London, the incentives for military support were dramatically changed. Now Finland fought "only" to keep as much as possible of her territory in Leningrad's neighbourhood. But of course the public could know nothing about this neither in Finland, nor abroad. For public opinion, Finland's fight remained a life and death struggle.

Franco-British support was offered on the condition it was given free passage through neutral Norway and Sweden instead of taking the road from Petsamo. The reason was a wish to occupy the iron ore districts in Kiruna and Malmberget. (Borders as of 19201940.)
In February 1940 the Allies offered to help: The Allied plan, approved on February 5 by the Allied High Command, consisted of 100,000 British and 35,000 French troops that were to disembark at the Norwegian port of Narvik and allegedly support Finland via Sweden while securing the supply routes along the way. The plan was agreed to be launched on March 20 under the condition that the Finns plead for help. It was hoped that this would eventually bring the two still neutral Nordic countries, Norway and Sweden to the Allied side by strengthening their positions against Germany, although Hitler already in December had declared to the Swedish government that Western troops on Swedish soil immediately would provoke a German invasion.
However, only a small fraction of the troops was intended for Finland. Proposals to enter Finland directly, via the ice-free harbour of Petsamo, were dismissed. Suspicions that the objective of the operation was to capture and occupy the Norwegian shipping harbour of Narvik and the vast mountainous areas of the North-Swedish iron ore fields from where the Third Reich received a large share of the iron ore critical for the war production, and fear of thereby becoming the battle ground for the armies of the Allied and the Third Reich, caused Norway and Sweden to deny transit. After the war it became known that the commander of the Allied expedition force actually was instructed to avoid combat contact with the Soviet troops.
The Franco-British plan hoped to capture all of Scandinavia north of a line StockholmGöteborg or StockholmOslo, i.e. the British concept of the Lake line following the lakes of Mälaren, Hjälmaren, and Vänern, which would contribute with good natural defence some 1,7001,900 kilometres south for Narvik. The expected frontier, the Lake line, involved not only Sweden's two largest cities, but its consequence was that the homes of the vast majority of the Swedes would be either Nazi-occupied or in the very war zone.
The Swedish government, headed by Prime Minister Per Albin Hansson, declined to allow transit of armed troops through Swedish territory. Although Sweden had not declared herself neutral in the Winter War, she was neutral in the war between France and Britain on one side and the Third Reich and the Soviet Union on the other. Granting transit rights to a Franco-British corps were at that time considered too great a diversion from international laws on neutrality.
The Swedish Cabinet also decided to reject repeated pleas from the Finns for regular Swedish troops to be deployed in Finland, and in the end the Swedes also made it clear that their support in arms and munitions could not be maintained for much longer. Diplomatically, Finland was squeezed between Allied hopes for a prolonged war and Scandinavian fears of a continued war spreading to neighbouring countries (or of the surge of refugees that might result from a Finnish defeat). Also from Wilhelmstrasse distinct advice for peace and concessions arrived the concessions "could always later be mended."
While Berlin and Stockholm pressured Helsinki to accept peace also on bad conditions, Paris and London had the opposite objective. From time to time, different plans and figures were presented for the Finns. To start with, France and Britain promised to send 20,000 men to arrive by the end of February, although under the implicite condition that on their way to Finland they were given opportunity to occupy North-Scandinavia.
By the end of February, Finland's Commander-in-Chief, Field Marshal Mannerheim, was pessimistic about the military situation, which is why the government on February 29 decided to start peace negotiations. That same day, the Soviets commenced an attack against Vyborg.
When France and Britain realized that Finland was seriously considering a peace treaty, they gave a new offer for help: 50,000 men were to be sent, if Finland asked for help before March 12. But actually, only 6,000 of these would have been destined for Finland. The rest was intended to secure harbours, roads and iron ore fields on the way.
Additional Sources: www.answers.com
www.utb.boras.se
virtual.finland.fi
www.mil.fi
www.politicsforum.org
www.historyhouse.com
www.battlefield-site.co.uk
www.iremember.ru
hkkk.fi/~yrjola
www.colddeadhands.addr.com
mailer.fsu.edu
www.onwar.com
www.raatteenportti.fi
www.military-art.com