What's behind North Korea's latest act of aggression

On Tuesday, North Korea blew up the Inter-Korean Liaison Office, a symbol of a rare rapprochement in 2018 with South Korea. The move comes as North Korean rhetoric grows increasingly hostile. Nick Schifrin reports and talks to Jeongmin Kim of NK News, a website focused on the Korean Peninsula, about North Korea's recent aggression and what it means domestically, for South Korea and for the U.S.