The situation with North Korea reminds me of Iraq through the 90s. Iraq had no leverage, except to expel the weapons inspectors, and each time they did that, they were depicted as hiding weapons. But that's not the reason they'd typically did it -- it was simply the only way they could be heard. It got to the point where I could predict when they would kick out the inspectors and when they'd let them back in. Like if there was a regional conference that Israel was invited to and they were not, they'd kick out the inspectors to try to spoil/expose the conference -- and then let the inspectors back in before the U.S. attacked them for kicking them out.
(This shouldn't be confused with the fact that Richard Butler was the one -- as U.S. government behest -- who finally killed UNSCOM by withdrawing inspectors just before the Desert Fox bombing campaign.)