Sweden supported Finland as always.
It is known that at least 15,000 Swedes volunteered to fight alongside the Finns, with 10,000 accepted for training and 8,000 actually went to
Finland in organised units before the war ended.
The Swedish government and public also sent food, clothing, medicine, weapons and ammunition to aid the Finns during this conflict. This military aid included:
[4]
- 135,402 rifles, 347 machine guns, 450 light machine guns with 50,013,300 rounds of small arms ammunition;
- 144 field guns, 100 anti-aircraft guns and 92 anti-armour guns with 301,846 shells;
- 300 sea mines and 500 depth charges;
- 17 fighter aircraft, 5 light bombers, 1 DC-2 transport aircraft turned into bomber, and 3 reconnaissance aircraft, totally comprising 1/3 of the Swedish air force at the time.
It's not that simple. Swedish citizens provided help, but the Swedish government made some pretty harmful decisions. Here's a relatively brief run down:
Swedish volunteers
When the Winter War started, the government of Sweden actively suppressed any volunteer campaigns.
For example by 2.12.1939 the organisation for a Svenska Frikår containing 7 500 men to help in Northern Finland was laid out, but defence minister Sköld and prime minister Hansson forbade newspapers from writing about volunteer help to Finland. E.g. an advertisement labelled "Finlands sak är vår" (Finland's cause is ours) that also mentioned the accepting of volunteers at an office in Stockholm was seen by minister of justice Westmar as the recruitment of Swedish citizens into the service of a foreign country and therefore a breach of law. Because of this, many volunteers cancelled their applications and fresh applications stopped altogether. Later this ban on volunteer work was lifted, but they could never get it going on the same scale as it was before the ban.
On 6.12. PM Hansson laid out the new program for the Swedish government. This program contained things like prohibiting military aid to Finland, and prohibiting the equipping of volunteers from state stocks.
Later the PM secretly lifted the allowed maximum amount of volunteers first to 4 000, and eventually all the way to 16 000, but the damage was already done. The government also did give the volunteers use of 12 obsolete fighter aircraft, which is of course better than nothing.
Unfortunately the force of 8 000 Swedish volunteers had little impact on the war. A lot of them were not used to using weapons and required training which took time, and only few of them ever reached the front.
Material aid
I don't know your sources, because those figures differ from Mannerheim's:
-80 000 rifles
-500 machineguns
-85 AT guns
-112 field guns and howitzers
-104 AA guns
-50 million cartridges
-300 000 shells
-25 aircraft
-Fuel and other equipment
Some of these were given as loans and were returned after the Winter War.
Announcement of refusing to help with regular troops
16.2.1940 the government of Sweden publicly announced to the world that Sweden will not help Finland with regular troops. On 19.2. the king of Sweden gave another public announcement backing the government on the matter. This encouraged the Soviet Union in its demands, since it now knew that Sweden would not back Finland. At the very least, it would've been best for Finland if Sweden had remained silent.
In fact Finland's foreign minister Tanner told Sweden's PM Hansson that these announcements by the government and king cost Finland Viipuri and Sortavala, and that Sweden should've remained quiet. Viipuri was Finland's second largest city, with Sortavala being another important city in Finnish Karelia.
"It is hard to understand why the government of Sweden saw it necessary to make these public announcements, which with both their content and frame weakened our chances to get a tolerable peace - in Moscow on the other hand they of course brought satisfaction." -Mannerheim in his memoirs
Transit rights
Finland, England and France repeatedly tried getting the Swedish government to give transit rights to the Allies, so they could send help to Finland. The Swedes denied the Allies transit and threatened to rip up from the ground every single railway road leading to a port if the Allies landed on Swedish soil.
Now of course I am aware that Norway also denied transit rights, and that the true primary objective of the Franco-British expedition was to occupy strategic places in Northern Scandinavia, such as the harbour of Narvik and the iron ore mines in Northern Sweden. It's quite possible that only a token force of a few thousand men would've actually reached Finland to help fight the Russians. Still, the threat of Franco-British involvement in the Winter War was enough to bring Stalin to the negotiating table and give up trying to take over all of Finland for the short time being.
Also, interestingly the Polish government in exile had wanted to send 20 000 Polish soldiers to Finland through Sweden once the Winter War had begun. These soldiers were still in Latvia and Lithuania after the fall of Poland. Sweden however denied them access. One can of course speculate if the Poles would've been able to pull it off, even if they were granted access.
Sweden as intermediary to peace negotiations
Along with its public announcement in February 1940, the Swedish government's conduct as an intermediary in the peace negotiations was to Finland perhaps the most important and unfortunately also the most damaging act that official Sweden committed during the Winter War.
"I have talked with the marshal (Mannerheim), who has certain thoughts -- not proposals. Firstly, in the current state of affairs Sweden is unqualified as intermediary, because her main interest is to save her own skin. Therefore we must attempt to get another intermediary. The marshal on his behalf was thinking of the United States." -Finnish PM Ryti during a government cabinet meeting on 3.3.1940.
To pressure Sweden, Mannerheim even proposed to offer Åland to the USSR instead of Karelia and the Hanko Peninsula. This proposal was not accepted.
Basically Sweden wanted Finland to accept peace at all costs. That didn't make for a very good intermediary, and quite possibly cost us some land like the important industrial city of Enso. Enso and some other places weren't supposed to go to the Russians in the peace treaty, but the Russians took them anyway. But I won't go further into that now since it's a more complicated topic.
Altogether, the aid was and is appreciated. But it wasn't much, and could've been a lot more if not for the policies of the Swedish government.