In the United States, a powerful bi-partisan Senate committee directly monitors the intelligence services. Its report on the inability of the intelligence services, notably the CIA and the FBI, to prevent the September 11, 2001, terrorist attacks also contained a series of recommendations for restructuring these services to render them more effective.
民主环境中的情报部门通常都设立了监督机制，防止权力被人滥用，并通过对未能完成任务的高官进行惩戒来确保行动的有效性。在美国，由强大的两党参议院委员会直接监督情报部门的工作。参议院在有关情报部门，特别是中央情报局和联邦调查局，未能阻止2001年9月11日恐怖袭击事件的报告之中还提出了一系列的重组建议，旨在提高情报部门的效率。