When the Japanese empire was dismantled at the end of World War Two, Korea fell victim to the Cold War. It was divided into two spheres of influence along the 38th parallel. The Americans controlled south of the line - the Russians installed a communist regime in the north, later ceding influence to China.
The orders were to take everything that they can, and burn and ruin everything that they can't take. The idea was to destroy infrastructure completely so as to weaken the southern population and the southern support for the war. They would burn farms and pillage everything leaving nothing standing.
