Impossible to say definitely. North Korea military spending has been around 25% of its GDP, which is said to be one of the top reasons why its economy plateaud in the 70s. Would it have needed to be so high if they had annexed the whole peninsula, and would they had closed up like they did if they had decisively won the war? Perhaps not: Vietnam certainly did better.
Around 20 percent of their population got also killed during the war.
>Douglas visited Korea in the summer of 1952 and was stunned by the “misery, disease, pain and suffering, starvation” that had been “compounded” by air strikes. U.S. warplanes, having run out of military targets, had bombed farms, dams, factories, and hospitals. “I had seen the war-battered cities of Europe,” the Supreme Court justice confessed, “but I had not seen devastation until I had seen Korea.”
And instead of Marshall help they got global economic sanctions.
The carpet bombing of North Korea was one of the great war crimes in history. 15% of the population died. 85% of the buildings were destroyed. Many, many cities were wiped off the map forever.
All this for a country that had never offered the slightest threat to the United States.