Harold Hongju Koh is one of the America's leading scholars of international law. He is the Sterling Professor of International Law at Yale Law School, where he formerly served as the dean. He's also served as the Legal Advisor in the State Department and was the U.S. Assistant Secretary of State for Democracy, Human Rights and Labor.   Professor Koh is the author of the new book that examines the Trump administration's relationship with international law. His book, called "The Trump Administration and International Law" surveys issues in which the Trump administration has clashed with international law, including immigration and refugees, human rights, and climate change. Professor Koh concludes that forces of international law are far more resilient than we might expect, and in fact, Trump's power has been constrained by international law.    Professor Koh explains the process through which international law has so far been able to blunt some of Trump's more aggressive impulses.