As the proverbial workhorse of international economic law, investment arbitration is heavily relied upon around the globe. It has to cope with the demands of increasingly complex proceedings. At the same time, investment arbitration has come under close public scrutiny in the midst of heated political debate. Both of these factors have led to the field of investment protection being subject to continuous changes. Therefore, it presents an abundance of challenges in its interpretation and application. While these challenges are often deeply rooted in the doctrinal foundations of international law, they similarly surface during live arbitral proceedings. International Challenges in Investment Arbitration serves not only as a collection of recently debated issues in investment law; it also deals with the underlying fundamental questions at the intersection of investment arbitration and international law. The book is the product of the 1st Bucerius Law Journal Conference on International Investment Law & Arbitration. It combines the current state of knowledge, new perspectives on the topic as well as practical issues and will be of interest to researchers, academics and practitioners in the fields of international investment law, international economic law, regulation and comparative law.