Korea had labor and management. There would be less people, so less need for capital, less physical plant, less money. But Korea needed land, to expand.
100,000,000 lives were affected. They would have to leave. The landscape looked like the Book of Eli. It would take thirty years to walk across America east coast to west coast, from what used to be New York to San Francisco, or what used to be San Francisco.
There used to be a choice after California. Now it was just a turnpike, to South America. Brazil would have been ideal passage to S.A. But the Caribbean did not and would not support 100,000,000 lives. Its waters were filled with nuclear waste.
So Americans would have to traverse the wartorn lands they made in central America, El Salvador, Nicaragua. Would they be well received? But if they made it out alive, their new homestead would be Peru and the pristine waters of Lake Titicaca.