The emergence of international tribunals around the world coincide with the explosion of constitutional courts globally. When we look at both systems under the eyes of regime theory, similar behavioral patterns are repeated. States in their relations with the international tribunals mimic some elements related to the “checks and balances” logic found in the constitutional system of adjudication. By analyzing this phenomena the book is a response to the critique on the effectiveness of international adjudication and it offers a theoretical recount on how international courts are shaping state behavior.