AH: Korean Confederacy

Alternate History of the Korean Peninsula after 1910. 

Through contrived circumstances, the Land of Korea has become a world power, surviving occupation and withstanding divisions.

These member states are:

Han Republic
Choson Peoples' Republic
Yanbian Province
Manchuria
Northern Korean Empire

Basic premise cut short:

The Korean Royal Family sought refuge in the Russian Far East after the annexation by Japan. Persecution was greater than OTL. Christianity, Nationalism and Socialism both grew and syncretized, so Korean revolutionaries were either stripe or all of them. 

At the time of the Chinese Civil War, the Northern Korean Empire defended Manchuria, where the last Chinese Emperor, and a number of nationalists resided. Manchuria consolidates as a Constitutional Monarchy.

1945 saw the end of the war, and a prominent Christian Socialist hero, Kim Song-ju became the strongman for a unified Korean Peninsula. Seeing threat from both sides, the Unified Korean nation forged a confederacy with the NKE and Manchuria.

1972, the Seoul-Pyongyang Megalopolis is established, marking the Korean Confederacy a rising power. Bigger than OTL Japan and Korea, it is one of the biggest manufacturers of electronics, cars and industrial materials. It is also the biggest exporter of it's culture, popular music, art and animation.