Yes, absolutely I believe North Korea can be dealt with as a rational actor. I would suggest that the two developments you mentioned—the presence of the Canadians in North Korea for what was ultimately a humanitarian mission and North Korea's nuclear missile testing program—are completely unlinked. I would go to the second assessment you made, which is that it has no bearing on the nuclear and missile program of North Korea.
However, yes, they are rational. We can look at North Korea's nuclear and missile programs and assess that there are primarily two drivers for them. The first, of course, is to secure the regime, and we have to talk about what regime security means. I believe it means ensuring the continuity of a Kim-based leadership in North Korea, and deterrence assists in that aim by keeping the United States away from military action on the Korean Peninsula. Similarly, North Korea is driven in part by domestic politics as well. Here we have a leader who is trying to demonstrate legitimacy in an office that he has not held for very long and who is doing that on the back of nuclear- and missile-testing successes.
Both of those are rational goals for North Korea. Everything I've looked at in North Korea over the years in terms of their development suggests that they're perfectly rational. They just think about things that we might not.