Sir John Chilcot’s report into the Iraq war is the fifth official inquiry that has been held into the events leading up to the 2003 invasion. Each of its predecessors was swiftly dismissed as a whitewash that failed to reveal why Tony Blair took the fateful decision to topple Saddam Hussein.

After seven years, 150,000 documents and about ￡10m of costs, Sir John has produced something very different. His report is a comprehensive and coruscating indictment of British policymaking in the run-up to the conflict and its aftermath.

It will disappoint those who hoped Sir John would deliver a clear and decisive condemnation of Mr Blair’s role in the conflict. The main charge against the former prime minister has long been that he deliberately and knowingly lied to the public and parliament about the threat that Saddam posed directly to Britain and to the west.