If North Korea launches a nuclear-armed ballistic missile, one of the only things we know for sure about what will happen next is that the news will race around the world on classified networks using the designation reserved for the Pentagon’s highest-level alert, an “OPREP-3 PINNACLE NUCFLASH,” which signals a possible imminent nuclear war. After that, though, we know surprisingly little about what might unfold — particularly if a surprise attack managed to cripple Washington.