Final answer:
An immediate effect of the Korean War was the creation of the DMZ at the 38th parallel. Long-term, North Korea remains isolated with a struggling economy while South Korea has developed into a modern, industrialized democracy.
Step-by-step explanation:
One immediate effect of the Korean War was the establishment of a heavily fortified border close to the original 38th parallel that runs across the Korean Peninsula. This demarcation, known as the Demilitarized Zone (DMZ), stands as one of the most militarized borders in the world and continues to separate North and South Korea.
In terms of long-term differences, the two Koreas have followed vastly different developmental paths. North Korea, under its isolationist and communist policies, has remained a closed society with a centrally planned economy and has faced significant economic hardships, along with human rights issues. In contrast, South Korea embraced a capitalist economy and, buoyed by policies that encouraged industrialization and modernization, has become one of the world's leading economies with a vibrant, democratic society.