It is being said that Kim Jun Il is taking note of what happened to Ghadafi as regards regime change and going nuclear is his way of protecting himself and his regime. But that is not directly comparable. The overthrow of Ghadafi was triggered internally, with the west assisting with air supremacy. Saddam is a more comparable case - he was overthrown because he was actively threatening US and Western Interests. By aggressively testing missiles and carrying out nuclear weapons testing Kim Jun Il is threatening the US and thereby setting himself up as the next candidate for regime change.
We are not looking at an Afghanistan or even a Vietnam situation, and especially not an invasion. We are looking at dealing with massive troop concentrations and known nuclear facility locations. Prime targets for MOAB. How many does the US have? Is that what POTUS actually means by "fire and fury"? The recent use of MOAB against entrenched Taliban positions in Afghanistan always looked like an operational test of the weapon - and it appears to have been very effective.