North Korea claims that on Tuesday night, it tested a hydrogen bomb. If true, it was a typically aggressive act by an evil regime. The White House said, however, that Pyongyang was doing something quite different, but also typical — engaging in empty boasting to exaggerate the Hermit Kingdom’s martial strength.

Whatever happened on Tuesday night, the reanimated North Korean nuclear threat holds a lesson about what happens when Washington makes agreements with regimes that are, to their core, untrustworthy. It often extends the lives of those regimes and facilitates the crisis it is intended to avert. That, of course, is why the rogue regime is interested in achieving a deal.