The following are what I think are the most likely endgame scenarios.
First, it is in order from more likely to happen to least likely.
Second and it's very important to note that the Examples are just that examples, hypothetical examples, I don't really think that's what actually will happen, though it could.
1.) - Either PEACE or Atlantis collapse do to different priority of it's members goals, basically inner turmoil, political/military or otherwise.
[Example Scenario: Let's say Romania on it's own wants to conquer Norway but at the same time Sweden takes on the UK over Belgium regions (possibly) who do we side with... it doesn't matter Atlantis will never recover.]
2.) - A vital 'rouge' nation or nations from either alliance betrays it original alliance shifting the balance of power to one side causing the fall of the other alliance.
[Example Scenario: Let's say Romania defects to PEACE and starts a war against Norway, could we stop it...]
3.) - A 3rd Alliance of a mix PEACE and Atlantis members is founded.
[Example: Let's say all of North and South America, throw in Japan UK and Spain, sound good doesn't it.]
4.) - Conquest Victory : Our massive amount of Citizens in Atlantis finally become the force we have been waiting for, after a few months and out muscle PEACE. We take their lands one by one.
[Example: Spain takes Portugal. We divvy up France, Argentina will switch back to Atlantis get's its land back and is helped to take Brazil, dido for Australia (except the switching sides thing). Sweden, UK and Norway split Germany and Belgium. Italy is overrun by Romania and Spain. And India and China (I'm not sure what side China is on; lets say they take our side for this one like Argentina) take Pakistan and Iran, parts of turkey. We help Israel and Greece to re-establish themselves and take back all of their land and they dived up the rest of Turkey along with everyone else in Atlantis. Indonesia is divide by all of Atlantis' major powers. This sounds very Good to me.]
Do you have any more Endgame scenarios?
The original discussions on the forums.