In 1975, Japan’s External Trade Organization (JETRO), conducted a study that found North Korea with a $600 million trade deficit to Western countries. It paved the way for North Korea to become the first country in the Communist Bloc to default on its debts to the West, which refuted the then-common supposition that Communist countries repay their debts and make good borrowers.

After Western companies discovered that trading with North Korea was more trouble than it was worth, Pyongyang had to invent new ways to earn hard currency. One of the ways in which the regime earned foreign exchange was