CBS News correspondent Mark Phillips reports that if you were to stack the whole report up, it would be two feet high, but the conclusion is simple: going to war in Iraq was not justified by the evidence, and once then-President George Bush had decided on war, his counterpart, British Prime Minister Tony Blair, was his willing accomplice.
The report -- seven years in the making -- was compiled by retired U.K. civil servant Sir John Chilcot, who concluded that in 2003, there was "no imminent threat from Saddam Hussein," and the strategy of containing the threat that did exist, rather than launching an offensive military action, "could have been continued for some time."
Chilcot said Blair's government "chose to join the invasion of Iraq before the peaceful options had been exhausted... Military action at that time was not a last resort."
"Mr. Blair overestimated his ability to influence American decisions on Iraq," Chilcot said.
The question has always been whether Blair made a secret deal with Bush to support him in ousting Saddam Hussein, no matter what.
The inquiry cited a private letter sent from Blair to Bush in July 2002 -- eight months before the U.S.-led invasion -- assuring the American president that "I will be with you, whatever" he decided to do.
Blair told Bush that that toppling the Iraqi dictator was "the right thing to do," in spite of the risks, noting that the policy of containment carried inherent risks of its own.
The Iraqi dictator, they insisted, had stockpiles of biological and chemical weapons of mass destruction and was still trying to develop a nuclear bomb.
Chilcot said the inquiry had concluded that evidence given by Blair and Bush of those WMD stockpiles was "presented with a certainty that was not justified."
The Bush administration's long-stated intention was regime change.
Officially, Blair was trying to convince President Bush to wait while United Nations weapons inspectors were sent into Iraq to search the country for WMD. U.S. intelligence had insisted they would find them. But they never did.
The attack went ahead anyway. The war, and the civil war and insurgency that followed, cost the lives of more than 4,400 U.S. military personnel, 179 British soldiers and hundreds of thousands of Iraqis.
Responding to the Chilcot report on Wednesday, Blair released a statement saying he believed it should "lay to rest allegations of bad faith, lies or deceit. Whether people agree or disagree with my decision to take military action against Saddam Hussein; I took it in good faith and in what I believed to be the best interests of the country."
Blair added that the report did, however, "make real and material criticisms of preparation, planning, process and of the relationship with the United States. These are serious criticisms and they require serious answers. I will respond in detail to them later this afternoon. I will take full responsibility for any mistakes without exception or excuse."
The families of the British dead had long demanded an inquiry. But for those families, like bereaved father Peter Brierley, the report offers no solace for the loss of a son.
Asked by Phillips if he believed his son died defending Britain, Brierley did not hesitate: "Not at all, there was no threat to his country."
The Iraq Inquiry had another mandate; to determine whether the planning by the U.S. and the U.K. for a post-Saddam Iraq was adequate. The conclusion was that it was not.
The instability which followed turned Iraq from a country that was not a training ground for terrorists, into one that continues to be just that today.