North Korea’s recent threat to conduct an underground nuclear weapons test, its third, is provocative enough on its own. The North Korean nuclear weapons program is illegal, dangerous and destabilizing, has been widely condemned by the rest of the world and is even causing some tension (alas, probably relatively minor and temporary tension) in Pyongyang’s all-important relationship with China.
Some analysts fear, though, that an upcoming test could feature a uranium-fueled weapon, rendering it potentially even more provocative. North Korea has in the past used plutonium. Why would the switch to uranium matter? Here are four reasons.