Karen J Alter is Professor of Political Science and Law at Northwestern University and co-direcor at iCourts Center of Excellence at the Copenhagen University Faculty of Law.] Thanks so much to Tonya Putnam, Roger Alford, and Jacob Katz Cogan for their thoughtful commentaries. I appreciate their kind words, and their comments reflect one of my hopes for this book; that it will be a springboard for researching new and important questions about international courts and international law. I want to respond while echoing some of the questions they raise. My starting point for The New Terrain of International Law was the following question: If the ‘problem’ of international law is its lack of enforceability, then how does making the law enforceable affect the influence of international law? I cut into this very big question by focusing on a new set of institutions that were designed to address the enforceability gap in international law. The comments in this symposium push upon a number of choices I made as I then tried to make the project tractable. My first choice was to focus on the universe of permanent international courts, co-opting the definition of an IC created by the Project on International Courts and Tribunals (PICT). Alford’s commentary openly worries that others will follow me in focusing on PICT courts. I share this concern, which is why I discuss the limits of relying on PICT’s definition (p.70-77). For me, the most arbitrary part of the definition is its focus on permanent ICs. I decided to nonetheless catalogue permanent ICs because sticking to a plausible definition ensured that I was examining like institutions. Another related question I sometimes get is why I include ICs that exist but have no cases. This is where the benefits of PICT’s definition arise. We can see from my universe that permanence is neither necessary nor sufficient for IC effectiveness, and we can start to examine why like institutions have varied impact. This is a topic that Laurence Helfer and I have pursued through our in depth research on the Andean Court and on Africa’s ICs. I am already moving beyond PICT’s definition, as should we all. The New Terrain of International Law demonstrates the arbitrariness of focusing on permanent ICs by including as case-studies non-permanent bodies. The NAFTA case study, for example, discusses how the “permanent” WTO system proved no more able than the NAFTA system to address complaints about illegal US countervailing duties. The Chapter 5 discussion of the ICJ’s role in the Bahrain-Qatar dispute, and the same court’s ineffectiveness in resolving US-Iranian disputes, shows again that being a permanent IC, with preappointed judges and the jurisdiction to issue binding rulings, still does not necessarily improve IC effectiveness. Another step in moving beyond PICT’s definition is that Chapter 1 of the new Oxford Handbook on International Adjudication, which I co-authored with the author of PICT’s definition, Cesare Romano, excludes permanence from the definition of “adjudicatory bodies.” A second choice was to use structured case studies as the mode of investigating how the existence of an IC contributes (or not) to changes in state behavior in the direction indicated by the law. Nico Krisch addresses indirectly my case-study choice in his reply on EJIL:Talk!