Government security intelligence services have been the subject of numerous studies both before and since the attacks of September 11, 2001 (hereafter, “9/11”). These studies, generally undertaken by official government commissions or committees, were begun in the mid-1970s and early 1980s, following disclosures of abuses of citizens' rights by the FBI and CIA in the United States, and by the Royal Canadian Mounted Police (RCMP) and the Canadian Security Intelligence Service (CSIS) in Canada (for disclosures, see for instance Hersch). Triggered by allegations of abuse, the studies tended to take a legal-normative approach toward the review of intelligence services. Two prominent U.S. congressional reports came forth in 1976: that of the Senator Church inquiry (United States, 1976) and that of the Congressman Pike inquiry, leaked to the The Village Voice. In Canada since the late 1970s, one commission of inquiry reported on the RCMP Security Service – the McDonald Commission (Canada, 1981a, b) and two others, the Keable Commission (Québec, 1981) – and since the creation in 1985 of the Security Intelligence Review Committee (SIRC), which oversees the operations of CSIS, Canadian focused on the conformity of intelligence operations to Canadian law, including the Charter of Rights and Freedoms. Such legal normativeness is reflected also in books focusing on CSIS (Cléroux; Mitrovica).

By contrast, there are few U.S. or Canadian studies on the effectiveness of security intelligence and police services in the prevention of terrorism.