While North Korea has ramped up missile tests and deployments in recent years, it hasn't detonated a nuclear device in several years as South Korea reportedly considers building its own nuclear deterrence (Yahoo [Reuters], Deutsche Welle). For the purposes of this question, a "nuclear device" is one that is designed to produce a nuclear explosion utilizing the fission and/or fusion of nuclear fuel (e.g., Uranium-235, lithium deuteride). A radiological device (aka "dirty bomb") would not count (Nuclear Regulatory Commission). North Korea's most recent nuclear detonation was in 2017 (BBC). A device that produces an explosive detonation for a subcritical test is not considered a "nuclear device" that is designed to produce a nuclear explosion (National Nuclear Security Administration). Confused? Check our FAQ or ask us for help. To learn more about Good Judgment and Superforecasting, click here. To learn more about how you can become a Superforecaster, see here. For other posts from our Insights blog, click here.