Last date for submission of paper: unknown; Contact person: unknown; Scholars and practitioners have long argued that compliance with international rules often requires building institutions or other mechanisms to ease access to information about possible violations. This book introduces a different information problem -- disclosure dilemmas -- that requires equipping IOs with secrecy. States and firms often possess private information that sheds detailed light on the compliance of others with international rules. Yet fears of revealing intelligence sources or helping commercial rivals can deter them from disclosing it. Building a