More North Korean Weirdness: the Not Hydrogen Bomb

Two days ago North Korea exploded an atomic bomb, then announced to the world that they had actually detonated a hydrogen bomb. But setting off a hydrogen bomb is not something that can be concealed from sensors in the U.S. and Russia, so other governments knew even before the announcement that the explosion was not powerful enough to have been a hydrogen bomb. This had the peculiar effect of making everyone mad at North Korea and generating tense hearings at the U.N. Security Council, for nothing. Why? Was the hydrogen bomb claim just for domestic consumption, or did the North Koreans want to make everyone mad at them? Were they feeling ignored, since not even Republican presidential candidates had bothered to denounce them lately? Bizarre.