Useful Tips for Big Countries
Europe
Europe starts rich and democratic, it’s stable by default, you mostly just run 100% MC and unify it to save on Control Point cap. Running some Unity to get public opinion on your side never hurts but it’s more for protection from hostile councillors than for resting cohesion.
The big nation everything is unifying into should try and get to Democracy 10 and run Kn as necessary; Europe basically starts there anyway though.
Other big nations don’t start with unions, and have other issues. USA has a big inequality problem, you will need to run a lot of Welfare and probably some Reduce Unrest missions. Declaring war on its starting rivals like Cuba can give you some early boosts to Cohesion to get it to 5-ish.
USA is primarily taken as a military beat-stick, so after you’ve done enough Unity and Welfare to stabilise it it’s not uncommon to focus it on Miltech for a number of years, until you get to miltech 5+, which is more than enough to beat up an Alien invasion if you’re waiting for them at the landing site.
On the other end are poor but huge nations like India and China. Of the two, China is in a much much better state at game start, and has more expansion potential with the PAC. In both cases, you’d love to eventually have them up at around 55k GDPpc and full democracy with Education 12ish, but it will take many many years to get there.
How much Economy you run is a function of your CP cap – boosting their economy right at game start might put you over cap. One pip in unity should be enough to keep public opinion high forever, and the rest go into Knowledge. With so many pips in Knowledge resting Cohesion is irrelevant you’ll trend towards 5 even with the relatively high starting inequality of China.
China
(China also has the option of being absorbed into Taiwan for a free instant boost to Democracy, but unless you do the PAC first that loses you a lot of land and the PAC comes fairly late in tech; Basically, it’s reasonable to ignore this possibility but if you do plan on it and can afford the high CP cap usage, perhaps due to self-imposed limits on taking other countries, then you worry a lot less about running Knowledge in China early and focus more on Economy).
Basically, in the long run all that matters is population, which means China or in the very late-game the Caliphate( which can absorb the African Union in addition to Oceania via Greater Indonesia, along with of course the middle east, and about half of the Indian subcontinent).
One often cares about the short run though, and that means looking at starting values, which means that for Military you’re grabbing the USA with its high starting miltech and 6 armies with navies. Europe is perfect for MC because it’s rich and starts divided and already in a federation, so it’s both efficient to invest in MC – this is much more efficient in small countries – and also fast to unify upo those small countries when the MC is done, to save on control point cap.
Note: I also suggest to consider IGNORING democracy & knowledge in large countries. Get at least 47.5k GDP per capita and drop everything into MC – research universities are much more efficient then Earth science (linear scaling). As bonus (if you aren’t going for quick victory & keep investing into Eco) you will get a better pop growth and eventually became invulnerable to anyone but aliens themselves.
Good breakdown, very well summarised. I have some quibbles about your formatting decisions – namely, the lack of them – but this is just about the most concise breakdown you could provide that still includes everything one might want to know about managing large countries