North Korea: Messing With Their Heads?

Was the big bomb the U.S. just dropped on Afghanistan really a message to North Korea? Josh Marshall at Talking Points Memo thinks it's possible:

We are currently in a tense brinksmanship with North Korea. If we did get into a military confrontation with North Korea, a big part of that would almost certainly be destroying heavily, heavily fortified facilities tied to the nuclear weapons and ballistic missile programs. I’m not a military expert. I don’t know the precise mix of primary blast versus concussion wave, the technical issues with destroying a nuclear weapons facility with the potential to spread nuclear contaminants, how deep the blast goes in fortified underground facilities, whether it’s good at destroying deep, reinforced bunkers rather than tunnels created by low tech paramilitaries, etc. etc. But I have a very hard time believing the decision to use this weapon was not in some way influenced by the desire to send a signal or play a bit of psychological warfare with the North Koreans. The technical issues don’t necessarily matter. If you want to rattle the North Koreans it can work anyway. They don’t know all the technical realities, limitations or how risky a game we might be willing to play. It may be enough to send the signal that Trump doesn’t operate by the rules of his predecessors. Maybe I’m wrong. But it’s a helluva coincidence. (Read the article here.)