Why is North Korea Suddenly Launching So Many Missile Tests?

North Korea has already launched more than six missile tests since the start of the new year. Why is North Korea is suddenly launching so many new missile tests -- and what can be done about?  Three experts weigh in: Jeffrey Lewis is a Professor at the Middlebury Institute of International Studies at Monterrey and an open source researcher at the James Martin Center for non proliferation studies Ankit Panda is a senior fellow at the Carnegie Endowment for International Peace Michelle Kae is the Deputy Director of the 38 North Program at the Stimson Center