Looking at how the main nations people choose in the game seem to be the United States and Great Britain (with Pirates coming next probably) people have been looking for a way to encourage people to play the "smaller nations" such as Sweden. While I believe we still should keep thinking of ways for people to be encouraged to choose the smaller nations I think there is one simple thing that could be done as a start.
When I first joined the game I looked at all the nation descriptions to see which I liked the best. I of course saw the US was labeled as Easy and when I was just starting I didn't want to learn this new game by being thrown into the deep end so I joined the US. After about 2 weeks I felt I had learned enough to go to a harder nation and went with Sweden. I expected some sort of difficulty change but I found none. The only difficulty we had was a smaller population. I feel this part of the description is misleading and should be changed.
While not top priority it seems like an easy fix and could be a good step towards keeping nations somewhat balanced. I will also attach the current nation descriptions for the US and Sweden and a possible idea for how to change them.