For example, saying Scandinavia could not be a major power isn't actually accurate. Individually, Denmark, Norway, and Sweden were all major world powers at points in history.
Let me rephrase: based on Aurora's mechanics, unless there is some very specific back story (like plague or nuclear war) small nations cannot become major players by themselves due to population size. Even if you start with the assumption that Scandinavia has the same industry/research as China (which is not true) they will loose simply due to having barely 3% as large a population, which translates to less factories that could be used and less wealth generated. The way around it is to create a large coalition centered around your chosen state, but it runs into two problems.
First, let's take EU for example. IIRC the 'Big Four' (UK, France, Germany and Italy) if working together have de facto the power of veto in any vote. This translates to the de facto control of EU policy. However is anyone ever saying "The (insert name here) led power block based on most of the Europe?" or are they saying (and thinking) "European Union"? Because that's how most power blocks in Aurora games work, creators make power blocks, which may or may not have a clear leader, and just use them. Because of this there are very few instances where single nations play pivotal role. And they practically never are a force of their own.
Second, times change. Using British Empire as an example of a small nation being a significant power is no longer as relevant as it used to be, because those were times with incredible technology imbalances and different ways of performing diplomacy. Basically English had everyone at gunpoint - and they have lost most of their territory by now. There is not a single colonial empire left. Not one. Which means unless the setting features a change of politics, it is almost impossible for a single nation, especially small one, to dominate any organization enough to become a power of it's own. Simple manning requirements (as used in Aurora) will mean that foreigners will have to play an enormous role.
All of this means that in any setting featuring world more or less as currently existing, small nations without enough manpower simply do not have enough significance to become major players on their own. They may become a center of a larger organization, but nowhere near as much as UK was the heart of the British Empire.
Again, please note that I'm talking about politics/economy as relevant to Aurora game play, not reality. On the other hand I cannot think of a single example where a single, small nation can unilaterally draw on manpower and resources of numerous, multi-million population nations. Even trade powers, like Singapore, simply generate money due to their geographic position, but they cannot possibly draw on manpower, military and resources of those they trade with.
Also I seem to remember an interesting quote. It goes more or less like this: "When goods do not cross the boarders, armies do." So if a small nation (like Taiwan made in an example earlier) tried to hoard enormous amounts of TN elements for themselves and use them as a leverage less than wisely someone might decide to "liberate" them. Things like this happen all the time after all.