Key point: Deterrence has been key to the North's survival.
Would the Trump administration actually consider invading North Korea?
First of all, it goes without saying I hope this never happens. However, history tells us we must plan for the worst.
So what would military action against the DPRK look like? While there are no certainties in modern warfare, one thing is certain: an attack on North Korea to rid the world of what can only be described as the most vile regime on the planet could be an unmitigated disaster.
As I explained in a debate for the Week in 2014, there is four reasons a regime-change-style invasion of North Korea would be insane. First, Kim has likely read a history book in the last twenty years:
Suppose Washington did decide to dispose of the evil thugs in Pyongyang. How would it proceed? It would start by heavily bolstering the amount of military assets within striking distance of North Korea. This would involve bringing in multiple aircraft carrier battle groups, increasing the number of troops in South Korea for a ground invasion, moving in large amounts of land-based aircraft, and boosting missile defenses in South Korea, Japan, and allied bases. In many respects, the U.S. would be dusting off an integral component of the 1991 Gulf War playbook — build a large attack force that can overwhelm the enemy. Simple, right?
The problem is that such a massive military mobilization can't be hidden. North Korea would instantly realize what was up. Pyongyang would certainly have a clear incentive to strike hard and fast knowing it constituted its best chance for survival. Here we see the great folly of Saddam Hussein: allowing coalition forces to build one of the world's most powerful fighting forces on his doorstep. Kim would realize his best chance — maybe his only chance — would be to strike with everything in his arsenal at the first sign of a build-up.
Second, North Korea would have every reason to launch a nuclear war: