Its been bugging me that I couldn't find a writeup on the Scandinavian Union, and in going through my library I finally found where it's discussed: the 2004 Shadows of Europe pgs 130-146.
Some select tidbits from that volume on the Sixth World's version of Scandinavia:
The political structure of the Union: Legally, there top of the executive is a 40 member Council of Ministers, with 10 representatives coming from each of the 4 countries of the Union. For legal matters beneath the Council of Ministers' attention there's the Union Parliament. The Ministers and Parliament administer the Scandinavian Commission, which is the EU-like body that is the Bureaucracy that runs the Union. On paper, the Union is supposed to act as a single unified country and internal borders have largely been dissolved, but there's still disparities in wealth and influence (Sweden is the most prosperous and influential in the Union government, while Norway is the poorest and least influential).
Interesting structure. I can imagine how this ended up being subverted and softly coup'D by the point the campaign will be at.
Denmark: Described as being squished between the SU and the rest of Europe and the megacorps (SK and Maersk), trying to please everyone.
Finland: Experienced an upsurge in forest growth since the Awakening and is summed up as "a beautiful country or a thousand lakes, sauna, and primeval forests".
More lumber is always good. I've already decided what ended up happening to Maersk for the sake of the campaign since I was aware of them beforehand.
Norway: "Once a prosperous country, Norway has been transformed into a poor, bleak and dreary bureaucratic nightmare and shadow haven". Oslo is also described as being the hub of Shadow activity in Scandinavia. Norway has the most poor and SINless and the most megacorporate evil overlording shenanigans.
Considering the kind of resources Norway sits on, this doesn't make any sense to me. While I could see the oil having run out by the 2070s(or whats left being in areas where its illegal to drill), I don't see the thorium doing so. Not to mention the oil fund itself. So this strikes me as a case of "Did Not Do The Research". Thus I'm pretty much just gonna blatantly retcon this part. Thank you for the information though.

Sweden: "With the aid of magic and technology, Sweden has gone from being green to being an eco-freak's paradise; a place where pollution is criminal and any infraction is treated like a mortal sin." Sweden is described as being the most hostile European country to the megacorps, and Stockholm is one of the most technologically advanced sprawls in the world.
An interesting tidbit.
The Sami- They've not yet formally agitated for a NAN-like secession, but there are rumblings to do so.
If they tried, they'd fail hard. They don't have the resources or population number to succeed at anything like that. Especially not in the circumstances the SU will be in at the start of this campaign.
Organized Crime: Three syndicates vie for the SU pie: The Russian Vory, the Japanese Yakuza, and the domestic syndicate called the Vikings. The Vikings are primarily smugglers, and smaller time than either of the international syndicates.
Hm this will prove useful for plot stuff once I've figured out a way to make use of it.
Scandinavian Corps:
Tyr, inc (Denmark) Security consultants, privatized prisons, mercenaries, owns a large corporate extraterritorial trading port in Copenhagen. Rivals of Maersk.
Erika (Finland) Big influence in the Matrix. Helped design the wireless matrix of the post-Crash 2.0 world.
Hydrolux (Sweden) Big eco-friendly energy corp (or so their PR goes...)
Saab (Sweden) Manufacturing. (remember Saab is a big name in SR, especially in the high end luxury and sports cars world. Saab Dynamit and Gladius, anyone?)
Saeder-Krupp and Maersk: Both megacorps are already given lore in many other SR books. Between them they'v gobbled up the entire domestic crop of Norwegian corps. These two are the two biggest corps in Scandinavia (Saab is no 3)
Interesting information. Will help with planning the sequence of events that lead up to the situation the SU will be in at the start of the campaign.
Culture and Religion:
Lutheranism is unsurprisingly dominant across the Union. In Shadowrun's Sixth World, there's also a neo-Pagan Aesir movement based on the old Norse religion (esp popular with metahumans). There's also the Sami-inspired "Slida" movement across Scandinavia, where anti-technology back-to-nature types organize into small communities based on subsistence living (fishing, reindeer herding, talismongering, cottage industries, etc). There's a large degree of influence or friction (or both!) between the Slida, the Sami, and the Vikings.
I saw this mentioned in tidbits on the norse magic tradition that arose post-2010s that the asatru had been spreading a fair bit due to all the things thats been taking place.
Some of my own further thoughts on a SU-TPA war:
I don't think occupying territory in Greenland, former Canada, or Siberia is in the cards for the SU or anyone at all for that matter. Outside of the TPA's four cities, the territory is ungovernable above the level of tribal complexity. If anyone WERE to try to invade and occupy the wilds of Greenland, Siberia or Canada the locals would just leave and hunt seals somewhere else, and the occupation forces are just sitting on frozen tundra for no reason other than to suffer the attacks by vengeful shamans, spirits, and god only knows what kind of para-critters might come at them off the ice.
If they run away from Greenland, thats a bonus for the SU. It saves them from dealing with the population. Plus since this is future warfare, the occupation forces don't need to spread across the entirety of greenland. Drone surveillance, war-drones, remote controlled war machines, etc designed to deal with the climate will serve well in patrolling the interior and the coast alongside a naval blockade. I've already given thought to how the shamans and spirits would be dealt with by the SU since I figured thats how TPA would primarily fight back until they can get the rest of NAN to react.
As I opined upthread, Iceland and Svalbard could be an exception, but only because they're islands. The SU can quarantine those landmasses via naval blockade and limit any opposition they face to whatever was caught on island at the onset of the occupation, plus whatever forces can be smuggled in through the blockade.
Both of those would fall very quickly yes given their circumstances.
Most nations of the Sixth world lack the military projection to engage in major invasions. Inuvik, Godth, and Norvik are all just too far from Scandinavia to launch, much less maintain, military occupations. There'd have to be megacorporate military involvement for anything like that to occur, and that sort of direct overt involvement is something that the megacorps rarely do. Examples of this happening are very few and far between in the SR lore (Yucatan, Tsimshian... not any others coming to mind). It's one thing for SK or Maersk to allow their naval forces be used to help "quarantine" Iceland/Svalbard, it's quite another to be overtly involved in helping one country take over another one.
By the point the campaign happens(we set it in 2078), the SU has been building up militarily for a long time(two to three decades to be precise) and will thus blockade the siberian and canadian areas of TPA as best as they can. Not that they're interested in directly taking anything in siberia or canadas mainland mind you. They are only after Iceland, Svalbard and Greenland(originally just southern Greenland, but given TPA's structure, I imagine diplomatic talks and pressures went nowhere). Though they would be happy if TPA seized to exist since controlling the arctic shelf to such a degree wouldn't be anything to scoff at.
There'd absolutely be a major home-front problem for the SU in the Sami and Slida assuredly being politically against the war. Domestic insurrection could very well be a possibility. There'd also likely be divisions inside the SU Council and Parliament on the topic of whether the Union should be prosecuting a war of aggression.. Sweden and Finland would assuredly being against, Norway being for it between nationalistic nostalgia and Corp pressure, Denmark would have to start being pro-war or else it'd never launch.. probably to go along with Norway and megacorps.. but Denmark's continuing political support for the invasion could very well be questionable as time goes on.
As I mentioned earlier in the thread, the SU's governing bodies have been hit by a soft coup d'etat. On the surface it'd seem like business as usual, but in reality at the point the campaign begins, the SU is essentially run by a dictator and absolute monarch. Meaning that publically the governments would be all in on supporting the war. That isn't to say there wouldn't be rumblings, but given part of the set up is that the SU is suffering from a major nationalistic movement at this point(a scandinavist nationalist movement to be exact), the majority support would be somewhat jingoistic.
As for the sami, they are so outnumbered that they couldn't offer any actual problem outside of terrorism. Politicially speaking they are simply not big enough to offer an obstacle. I could see them being split on the issue though, but they'd have no reason to be positive towards the enemy. Keep in mind that by the point the war breaks out, TPA and NAN has basically been the target of a very extended proganda campaign where they'd be blamed for a lot of ills suffered in the SU by its people. Thus many of them might not be pro-war, but they wouldn't be likely to do anything drastic about it either or support its enemies for the most part.
The starting point would be as the lore has framed things(despite certain things not making sense), but for the sake of the plot and fun, I've diverged the timeline decades before the campaign takes place to set things up to evolve the SU's situation into a point where it is willing and capable of taking back Greenland, Iceland and Svalbard. Whether that happens or not after the campaign starts is anyones guess.
Anyway thanks for all the information you managed to dig up. It'll prove very useful in fleshing out the full scenario that'll set the stage for the campaign. Which will help make it more enjoyable for the participants.
