North Korea’s leader, Kim Jong Un, has just signalled its nuclear ambitions at sea by saying that the country should build two warships every year in the next five years. Mike Chinoy, a former CNN senior Asia correspondent, who has made 17 trips to Pyongyang, shared his insights on Kim and discussed a new book, “Miss Kathi: Saving Lives in North Korea,” which he co-authored with Swiss aid worker Kathi Zellweger.