This week, The Cipher Brief's National Security Reporter and Europe Analyst Kaitlin Lavinder speaks with Ambassador Alexander Vershbow, former Deputy Secretary General of NATO (2012-2016). A changing external threat environment, internal security concerns, and the rise of populist anti-EU political parties leave Europe in a vulnerable position in 2017. Alexander tells Kaitlin how NATO can play a vital role in European security, and how the United States plays an indispensable role.