What *exactly* are the requirements for unification?

[Dainchi]

I've been trying to unify quite a few countries, but some notable examples (especially Unified Europe + UK and North Korea + South Korea) seem to fail, despite having claims on one another and being allied, and (in the case of the UK) being in the same federation.

It seems as though I'm fulfilling all the requirements in the tooltip for unification, but I don't have the option.

Is there a society tech that unlocks this or am I just missing something?

[DeadTried]

if you go to manage relations with a country there is a cooldown like a year or so for a nation to join a federation or unify.
The requirements for unification are to be in the same federation and have full control over the two countries i believe, and not have the relation change cooldown

[Dainchi]

Originally posted by DeadTried:

if you go to manage relations with a country there is a cooldown like a year or so for a nation to join a federation or unify.
The requirements for unification are to be in the same federation and have full control over the two countries i believe, and not have the relation change cooldown

Ahh, I didn't see the cooldown.
That makes a lot of sense, thanks!