7 July London bombings intelligence review

Following the 7 July 2005 bombings, the Intelligence and Security Committee (ISC) was tasked with investigating what the UK security services (MI5) and police knew about the attackers before the event. Unlike the Coroner’s Inquest, which focused on the victims and the immediate response, the ISC report dealt with the "secret" history of the plot. The investigation was released in two main phases: a preliminary report in May 2006 and a more detailed, 100-page review in May 2009 titled "Could 7/7 Have Been Prevented?"

The 2006 report revealed that Mohammad Sidique Khan (the ringleader) and Shehzad Tanweer had appeared on the periphery of "Operation Crevice"—a previous surveillance operation into a different fertiliser bomb plot in 2004. However, they were not identified as high-priority targets at that time. The 2009 review went deeper, investigating why MI5 had not "joined the dots" on Khan, whose name had appeared in multiple databases linked to various addresses and telephone numbers.

The inquiry found that MI5 was operating under immense pressure, with its resources stretched to the limit by an ever-growing list of "A-list" terror targets. Khan and Tanweer were categorized as "desirable" rather than "essential" to investigate. The report concluded that MI5 had behaved reasonably given the intelligence they had and the finite resources at their disposal. It rejected claims of a "cover-up" but was critical of the lack of transparency regarding national threat levels, which at the time were kept secret from the public.

By 2026, this report is viewed as the catalyst for the modern "data-led" approach to British counter-terrorism. It led to a massive expansion of MI5’s budget and staff, as well as the creation of the Joint Terrorism Analysis Centre (JTAC). It also forced a fundamental shift in how the government communicates danger to the public, moving away from secret classifications to the public threat-level system (Critical, Severe, etc.) that remains in use today.