SEOUL—North Korea’s latest threat—to detonate a hydrogen bomb over the Pacific Ocean—if carried through would mark a new level of defiance in the face of warnings from the U.S. and the international community. Pyongyang has notched milestone after milestone this year in its quest to develop a nuclear-tipped missile capable of striking the continental U.S., each time causing a furor and inviting toughly worded responses from President...

Source: Wall Street Journal September 22, 2017 11:26 UTC