In 13 years, a new organizational complex emerged in the United States to carry out intelligence and security activities, one that departed significantly from the National Security Law (1947). In the modified version of rational institutionalism developed by Amy Zegart, such a result would be unlikely. To explain this apparent anomaly, we resort to the notion of institutional drift proposed by Hacker, Pierson e Thelen and describe the interactional dynamics between states, organizations and leaders, with their structural implications as suggested by Falleti e Mahoney.