The Song Dynasty (900-1200 CE/AD) was technically the first to industrialize. They were the first known to have assembly lines and they had very advanced technology, but due to their Confucianist ideals they weren't as expansionist and imperialist as Europe which means they didnt spread this at all... so once they were defeated, so was this small burst of industrialism.
With the end of WW2 korea was one of a whole. Until USA and Russia established a line through it. Soviet Union in the north and USA in the south. Both wanted korea to be a whole but neither would give up a side.
