In this Executive Summary, the Inquiry sets out its conclusions on a number of issues that have been central to the controversies surrounding Iraq. In addition to the factors that shaped the decision to take military action in March 2003 without support for an authorising resolution in the UN Security Council, they are: the assessments of Iraqi WMD capabilities by the intelligence community prior to the invasion (including their presentation in the September 2002 dossier); advice on whether military action would be legal; the lack of adequate preparation for the post‑conflict period and the consequent struggle to cope with the deteriorating security situation in Iraq after the invasion. This summary also contains the Inquiry’s key findings and a compilation of lessons, from the conclusions of individual sections of the report.