Project Atlas is a modded Minecraft server on 1.20.1 that uses a Europe map and goes heavy on geopolitics and war.
You can pick a nation and do stuff like fly fighter jets fight on the frontlines or lead a tank division. You can also try to be the president emperor or dictator if you want.
It is free to play and there is no application. You can start your own defense company or trade company or even make your own nation. The server is new and it plans to release when it hits 25 members.
Worldbound SMP is a geopolitical survival server where the world is still empty and the first nations are starting to appear. Players make their own nations and then try to grow them into something big.
The map is built from a satellite style world which means you get realistic continents and oceans. It feels like you are building a real civilization on a real planet.
People build cities and capitals and set borders then they make alliances and do diplomacy. If talks fail then nations can fight wars that change the map and the story.
It supports Java and Bedrock crossplay and it runs on 1.21.1 and up. Early players can end up as major leaders while the world is still getting shaped.