1. FIZZLE? SOMETHING EXPLODED, BUT NOBODY SEEMS TO KNOW WHAT.
There was a seismic event near Kilju, North Korea. The signature was characteristic of an explosion: a sharp leading edge, unlike the release of elastic energy in a tectonic movement. But so far there is no report of airborne radioactivity, which is the most reliable evidence of a test and says the most about what sort of nuclear device it was. North Korea says it was deep underground, but there is typically some venting. If it was a nuclear bomb, it was very small. Bomb freaks in the Pentagon hyperventilate at the thought of a mini-nuke, but a fizzle would be more likely.
Not to mention a mini-nuke would indicate a level of sophistication beyond North Korea’s current nuclear capabilities.