It would be fun to see a Paradox game without ANY warfare. War might exist, but you cannot take part directly. You head a nation, and if war breaks out, you care for the financing and the supplies and the public opinion and revolts and shortages and production, but the war happens "by itself", aka the outcome is calculated by taking in factors such as technology, army reforms, manpower, supply, wealth, familiarity with the terrain, distance, etc.
It would be interesting to me because then Paradox would have to come up with peace-time/peaceful content, without having warfare overshadow the game so much that most design and programming resources go into that. If your main focus is administrative and diplomatic and organizational, then there would have to be massive content for that.
Now that would be a fine game! But Paradox is still (four iterations down the road) linking the taking of loans to inflation. (My avatar-name has been the same for a long while!) So while I like their games very much, I think they'd need to set up a complete new sub-division to get that game rolling.