AHC/WI North Korea wins the korean war and unifies the peninsula?

This is plausible. No Hyundai, Kia, LG,etc. Less competition for Japan, unless another country fills the void.
South Vietnam? No American troops in South Korea means more troops for Vietnam, so, perhaps, we could see a divided Vietnam and a united Korea. One major thing is that 'Murica will have an enormous case of victory disease, so I forsee quite a lot of adventuring in Israel - maybe a Netanyhu-style hawkish Israeli president comes to power? Another major thing is the anti-Vietnam counterculture will now have egg on their faces, given the Americans' victory.

On the plus side, my London secondary school will not be infested with Year 7s and 8s moaning on about how they want to snog BTS! :p
 
Top