Chapter 2 presents our core concepts, develops our theoretical logic, and derives hypotheses for empirical testing. The chapter defines our key terms and discusses the scope conditions on our theory. We then elaborate on what kinds of information are considered sensitive in our framework and describe the kinds of problems that can arise when such information is necessary for understanding compliance-related questions. We next expand on the necessary features of IOs’ confidentiality systems, providing concrete examples. The chapter concludes by developing our two core empirical expectations about the effect of confidentiality systems on the frequency of disclosures of sensitive information and on international cooperation.