It has made a steady stream of diplomats, army generals and senior mandarins rake over their role in one of the most disputed foreign policy decisions in modern British history, while its proceedings have attracted controversy over soft questioning, misleading witnesses and missing evidence.
Yet, as its first four weeks of public hearings draws to a close, Sir John Chilcot's inquiry into the decision to invade Iraq has already exposed a string of failings within the British Government during the 70 hours of testimony given by the 38 witnesses that have appeared so far. One theme has emerged above all others.
"This time, in contrast to previous inquiries, where it becomes essential, they are prepared to leave Blair in the firing line," said Brian Jones, a former Ministry of Defence intelligence analyst. It is not just disgruntled civil servants or under-resourced military chiefs hitting back, either. Even former advisers have left the inquiry ensuring that Mr Blair has more awkward questions to answer.
While the former head of MI6, Sir John Scarlett, told the committee that Mr Blair had been made aware of last-minute intelligence that Saddam Hussein's weapons had been dismantled, his personal adviser also weighed in this week. Sir John Sawers, foreign affairs adviser to the former Prime Minister, said he did not share Mr Blair's confidence that invading had been the right decision. "Frankly, had we known the scale of the violence, it might well have led to second thoughts about the entire project," he said. Sir Jeremy Greenstock, who served as a special representative in Baghdad, added that Mr Blair had told him to make improving the media image of the situation in Iraq a priority, and accused him of giving him an unrealistic target for training Iraqi police.
Cut out by the US
Though Mr Blair has been left exposed by his decision to back the US-led invasion, the early weeks of the inquiry have laid bare that both he and his Government were given precious little influence in return. Sir Christopher Meyer, the former ambassador in Washington, said Britain had gained almost nothing, save for the "applause factor" it garnered Mr Blair and British diplomats. "It is wonderful stuff being applauded wherever you go," he said. "I said to London, 'The key thing now, quite apart from Iraq, is to translate this popularity into real achievements'. We failed."
When it came to tackling the aftermath of the invasion, British officials were cut out of the loop. Sir Jeremy, who arrived in Baghdad in 2003, was blocked from becoming a deputy administrator in Iraq because Washington wanted to hold on to the decision-making. Paul Bremer, the US administrator of post-invasion Iraq, vetoed Sir Jeremy's appointment.
Catastrophic lack of planning
The failure by the US to plan for the aftermath of the war meant the growing insurgency became unmanageable. Mr Blair himself realised that the Office for Reconstruction and Humanitarian Assistance (ORHA), set up by the US to oversee the reconstruction effort, was "a shambles". But others have revealed there were also failures much closer to home.
Major General Tim Cross said the British Government failed in their own planning, leaving him isolated in the ORHA. Lt Gen Sir Robert Fry, deputy commander of the coalition forces after the invasion, said there was a "disappointing degree of traction" in Government planning. He painted a picture of a Cabinet split on the Iraq invasion paralysing decision-making. "Neither the nation nor Parliament, nor even the Cabinet were unified on the war," he said. Gordon Brown was also fingered for failing to provide the funds needed to cope with the worsening security situation in Basra, where British troops were based.
The missing questions
Questions remain about Iraq's weaponry and the identity of the source of the claims about missile stockpiles and the 45-minute timeframe. It is possible much of the intelligence relied upon to make the case for war was handed to the intelligence services by reliable sources, who were repeating the information second-hand. This is something the inquiry will be under pressure to reveal. The extent to which the Treasury withheld funds for the reconstruction effort has also become an important issue. As for Mr Blair, answers are needed on when he decided to back the war.
The inquiry committee has been criticised for its lack of rigour, but interested onlookers are hoping to be proved wrong. "Maybe everyone is being lulled into a false sense of not expecting much and they will come up with something rather more," Dr Jones said. "I hope so."
Five questions that Blair needs to answer
When did he decide that he would back the US in any military action? Was it as early as his meeting with President Bush in April 2002?
Does he accept that his foreword to the September 2002 dossier, which said that Saddam Hussein's possession of WMD was "beyond doubt", was overstated?
Why did he appear to throw away the influence he had over President Bush as his main ally in the war?
Why did he not delay the invasion after the warning from Maj Gen Tim Cross, two days before the invasion, that post-war planning wasn't ready?
Did he receive any intelligence that contradicted his claims in the 2002 September dossier on Iraq's WMD? It's alleged that he did in March 2003.