The question of a North Korean collapse is not "if" but "when"; after all it has no economy, can barely feed itself, and is run by an insane child/cadre of elderly generals and secret police enforcers who can only agree on not wanting to wind up in front of the Hague or torn apart by a starving mob.

This report lays out what might happen if North Korea collapses, and in brief it isn't pretty. A massive humanitarian crisis emerges in an already marginal region as military commanders factionalize and start trying to come out on top. ROK and US forces fight their way inland to secure hundreds of WMD bunkers before nukes and bioweapons can be sold on the black market. Meanwhile, nobody knows what China might do, ranging from take over half the job of securing North Korea and generally being helpful to declaring one faction the legitimate govt and starting WW3, and after the initial dust settles, South Korea has to figure out how to charge responsible parties with war crimes, allocate state owned property in a way that doens't displace North Koreans or piss off South Koreans sitting on 60 year old deeds.

Basically, it's a clusterfuck combining the worst aspects of East Germany, the 2003 Invasion of Iraq, and the ongoing Syrian Civil War. Bennett lays out the scope of the problem, but the solutions are fragmentary. All we can really do is prepare a psyops campaign on the North Koreans elites to convince them to allow an orderly collapse and transfer of power and predeploy the ground forces needed to secure WMDs and distribute humanitarian aid. From a methodological standpoint, Bennett treats the North Koreans and Chinese as basically inert forces of resistance, with no intentionality of their own. On the one hand, this is the Hermit Kingdom we're talking about, and accurate modelling is very hard. On the other hand, c'mon RAND, I expect better sources and analysis than a bunch of defector's blogs.

War is hard. Peace is harder.