North Korean military technology development has accelerated far faster than anticipated. This doesn’t represent a huge change of risk for South Korea, which has lived with a military threat from the North for a long time. But the risk to the US has gone from minimal threat to one that is plausible and large. This is a meaningful change that is driving a reaction from the US, and the form that takes may be relevant for global risk. That is the message from Professor Robert Kelly, a political analyst on inter-Korean affairs and associate professor in political science at Pusan National University in Korea.