The Wall Street Journal reported today that a North Korean closure of the Kaesong Industrial Complex would be a signal of increased probability of hostilities with South Korea. North Korea hosts the industrial complex a few miles within its boundary, where approximately 50,000 North Koreans work for 123 South Korean companies. On an average workday, about 120 South Korean managers cross the border into the complex. South Korean companies operating in the complex pay $80 million in cash wages directly to the North Korean government, and conduct approximately $2 billion worth of North Korean trade. This is a significant amount considering North Korea’s largest trading partner, China, yields only $6 billion worth of trade. The complex is a source of inexpensive labor for South Korea, rare US dollars for North Korea, and a foundation for pan-Korean economic and political cooperation (Reuters, WSJ).

North Korean threats and provocations are primarily bluster and bluff meant to elicit talks and appeasement payouts from the west. North Korean closure of the Kaesong Industrial Complex would be no different.

More informative signals would be: 1) South Korean closure of the border crossing, or 2) North Korean capture of South Korean complex workers by abruptly closing the border. The first of the two scenarios would indicate that South Korea believes hostility is imminent. The hostility could include the second scenario, or more seriously but less likely, a North Korean attack on South Korea. The capture of South Korean complex workers would be the most serious Korean crisis since 2010, when North Korea sunk a South Korean naval vessel and shelled a South Korean island. It would likely lead to US and Chinese-mediated negotiations, a payout to North Korea, and a definitive end to North Korea’s access to trade through the Kaesong Industrial Complex. Not North Korean, but South Korean closure of the border, is the signal to watch.