British Prime Minister Tony Blair told U.S. President George W. Bush eight months before the 2003 invasion of Iraq "I will be with you, whatever", and relied on flawed intelligence and legal advice to go to war, a seven-year inquiry concluded on Wednesday.
It strongly criticized Blair on a range of issues, saying the threat posed by Iraqi dictator Saddam Hussein's supposed weapons of mass destruction had been over-hyped and the planning for the aftermath of war had been inadequate.
Blair responded that he had taken the decision to go to war "in good faith", that he still believed it was better to remove Saddam, and that he did not see that action as the cause of terrorism today, in the Middle East or elsewhere.
The only Labour prime minister to win three general elections, Blair was in office for 10 years until 2007 and was hugely popular in his heyday, but Iraq has severely tarnished his reputation and legacy.
The inquiry report, about three times the length of the Bible, stopped short of saying the war was illegal, a stance that is certain to disappoint Blair's many critics.
"We have, however, concluded that the circumstances in which it was decided that there was a legal basis for military action were far from satisfactory," said John Chilcot, the inquiry's chairman, in a speech presenting his findings.
Blair said the report should exonerate him from accusations of lying, which have been made by relatives of some of the 179 British soldiers who died in the conflict.
"The report should lay to rest allegations of bad faith, lies or deceit," he said in a statement.
"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 over-estimated sway of Bush
Relatives of some of the British soldiers who died in Iraq said they would study the report to examine if there was a legal case to pursue against those responsible.
"We reserve the right, ourselves, to call specific parties to answer for their actions in the courts if such a process is found to be viable," said Roger Bacon, whose son died in the war, at a news conference just after Chilcot spoke.
The report shed light on what happened between Blair and Bush in the months leading up to the March 2003 invasion, an interaction that has long been the subject of speculation about secret deals and pledges.
In a memo dated July 28, 2002, eight months before the invasion, Blair told Bush: "I will be with you, whatever. But this is the moment to assess bluntly the difficulties."
"The planning on this and the strategy are the toughest yet. This is not Kosovo. This is not Afghanistan. It is not even the Gulf War."
Chilcot said Blair had sought to influence Bush’s decisions, offering Britain's support while suggesting possible adjustments to the U.S. position.
But the inquiry chairman added that Blair had over-estimated his ability to influence U.S. decisions on Iraq.
His report also said there was no imminent threat from Saddam at the time of the invasion in March 2003, and the chaos in Iraq and the region which followed should have been foreseen.
By 2009 at least 150,000 Iraqis, mostly civilians, had died, and more than a million had been displaced.
The report said Britain had joined the invasion without exhausting peaceful options and that it had undermined the authority of the United Nations Security Council by doing so.
"It is now clear that policy on Iraq was made on the basis of flawed intelligence and assessments. They were not challenged and they should have been," Chilcot said.
He also said that Blair's government's judgments about the threat posed by Iraq's weapons of mass destruction were "presented with unjustified certainty".
No such weapons were discovered after the war.
Chilcot said Blair changed his case for war from focusing on Iraq's alleged "vast stocks" of illegal weapons to Saddam having the intent to obtain such weapons and being in breach of U.N. resolutions.
"That was not, however, the explanation for military action he had given before the conflict," Chilcot said.
Iraq remains in chaos to this day. Islamic State controls large areas of the country and 250 people died on Saturday in Baghdad's worst car bombing since the U.S.-led coalition toppled Saddam.
The inquiry's purpose was for the British government to learn lessons from the invasion and occupation that followed.
"We cannot turn the clock back but we can ensure that lessons are learned and acted on," Conservative Prime Minister David Cameron told parliament in a statement on the inquiry.
"It is crucial to good decision-making that a prime minister establishes a climate in which it's safe for officials and other experts to challenge existing policy and question the views of ministers and the prime minister without fear or favor."
Jeremy Corbyn, the current leader of the Labour Party and a fervent pacifist, told parliament that the war was an act of aggression based on a false pretext that had fueled and spread terrorism across the Middle East.