To add to what Caleb said about Korea… Korea didn’t divide itself. It wasn’t an internal struggle that forced the division of the Koreas into 2 halves. Rather, Korea was forcibly divided by Washington (with Soviet consent) into North and South. In the South, the first president, Rhee, was not a SKorean resident who rose to political power with the support of the people. Rather he was man who lived in the US, selected by Washington, and subsequently transported to SKorea in order to serve as its first “democratically elected” president. In short, the SKorean government was a puppet regime; not democratic, but a brutal police state. As to whether NKorea “invaded” SKorea, that’s uncertain. Both sides were itching to reunite the country and border skirmishes were frequent. And to this day, it is the US that keeps the Koreas divided notwithstanding desires by both sides for detente.