what he might have to do or who he might have to owe in terms of the ability to sustain power. >> reporter: in fact, u.s. officials tell us that it is extre extremely difficult to get human intelligence on the inner workings of the regime. they're not as worried about the big grand scale attack, but they are worried about smaller provocations like shelling some of those islands there near south korea that could lead to a tit for tat response and really see things escalate on the peninsula. ka kate? >> this is just the latest in a string of threats as you well know and you've talked about. thanks so much from the pentagon for us this evening. let's dig deeper on this now with the veteran diplomatic troubleshooter, former new mexico governor and u.n. ambassador bill richardson. i don't need to remind our viewers, governor, but you have been to north korea a number of times and most recently just in january. thanks so much for coming in.