This Thematic Brief examines internal control in intelligence services with reference to the Euro-Atlantic area. It notes that considerations of oversight and control of intelligence services usually focus on external oversight — through parliamentary committees, the judiciary, or the executive — and that often less emphasis is placed on internal control mechanisms within intelligence services. It suggests that internal control is nevertheless as important as external oversight in ensuring that intelligence services act in accordance with the rule of law and with respect for human rights. It outlines challenges to ensuring effective internal control within intelligence services, and presents recommendations on how these may be overcome. 

The Brief is composed of five sections.
•    The first section defines key terms and concepts, and clarifies the scope of the Brief.
•    The second details the key prerequisites for an internal control system, focusing on the role of the executive branch in establishing legal parameters for intelligence services.
•    The third examines the key characteristics of internal control systems.
•    The fourth outlines common challenges to ensuring effective internal control, and
•    the final section provides recommendations on how to overcome these challenges.