https://steamcommunity.com/sharedfiles/filedetails/?id=1431410599
So I wrote this today. Pretty sure it's unbuggy. I was testing Cold Wars with the condition of a single Silo that didn't need Uranium, and they were too common, but three silos that each need 1 Uranium + Missile requirement might be too steep. Please leave feedback
-World Wars:
Whenever a Civilization that has chosen an Ideology goes to war with another Civilization that has chosen a different Ideology, a World War is declared and all other Civilizations following either of those Ideologies will follow their Ideological fellows into war, as long as they aren't breaking Declarations of Friendship, they haven't Denounced their fellow Civilization that started the World War, and they aren't currently in a Cold War with any Civilizations of the enemy Ideology. World Wars end when all of the Civilizations that adopted one of the two opposing Ideologies make peace with all of the Civilizations that picked the other.
Great War Infantry is no longer unlocked at Replaceable Parts. Instead, Riflemen upgrade straight to Infantry, and any Civilizations entering World Wars have their Musketmen, Riflemen, Mehal Sefari, Caroleans, Minutemen, and Norwegian Ski Infantry upgraded to Great War Infantry.
-Cold Wars:
The Missile Silo is a new building unlocked at Advanced Ballistics that requires having built at least one Nuclear Missile and consumes 1 Uranium. Whenever a Civilization builds its third Missile Silo, it enters into a Cold War with every other Civilization that has built at least three Missile Silos and has adopted a different Ideology, ceasing any current conventional hostilities and starting a permanent Mutually Assured Destruction peace that can't be broken until the Cold War ends. Cold Wars end when a Civilization has been forced to switch Ideologies.
So I wrote this today. Pretty sure it's unbuggy. I was testing Cold Wars with the condition of a single Silo that didn't need Uranium, and they were too common, but three silos that each need 1 Uranium + Missile requirement might be too steep. Please leave feedback

-World Wars:
Whenever a Civilization that has chosen an Ideology goes to war with another Civilization that has chosen a different Ideology, a World War is declared and all other Civilizations following either of those Ideologies will follow their Ideological fellows into war, as long as they aren't breaking Declarations of Friendship, they haven't Denounced their fellow Civilization that started the World War, and they aren't currently in a Cold War with any Civilizations of the enemy Ideology. World Wars end when all of the Civilizations that adopted one of the two opposing Ideologies make peace with all of the Civilizations that picked the other.
Great War Infantry is no longer unlocked at Replaceable Parts. Instead, Riflemen upgrade straight to Infantry, and any Civilizations entering World Wars have their Musketmen, Riflemen, Mehal Sefari, Caroleans, Minutemen, and Norwegian Ski Infantry upgraded to Great War Infantry.
-Cold Wars:
The Missile Silo is a new building unlocked at Advanced Ballistics that requires having built at least one Nuclear Missile and consumes 1 Uranium. Whenever a Civilization builds its third Missile Silo, it enters into a Cold War with every other Civilization that has built at least three Missile Silos and has adopted a different Ideology, ceasing any current conventional hostilities and starting a permanent Mutually Assured Destruction peace that can't be broken until the Cold War ends. Cold Wars end when a Civilization has been forced to switch Ideologies.