This week's episode of The Global Cable features Harold Hongju Koh, Sterling Professor of International Law at Yale Law School. One of the country's leading experts in international law and human rights, he served for many years in government under presidents of both parties, most recently as the 22nd Legal Adviser to the U.S. Department of State from 2009 to 2013.  On The Global Cable, Professor Koh talks to us about his new book, The Trump Administration and International Law, why 'America first' so often means 'America alone', and his perspective on impeachment proceedings against the President.