Tony Blair has expressed "regret" that he did not challenge intelligence about Saddam Hussein's supposed weapons of mass destruction but insisted he still believed he was right to overthrow the Iraqi dictator.
After the Chilcot report strongly criticised the way the former prime minister took the country to war in 2003 on the basis of "flawed" intelligence with inadequate preparation, he said the world would be in a "worse position" if Saddam remained in power.
"I can regret the mistakes and I can regret many things about it but I genuinely believe, not just that we acted out of good motives, and I did what I did out of good faith, but I sincerely believe that we would be in a worse position if we hadn't acted that way. I may be completely wrong about that," he told the BBC Radio 4 Today programme.
"I understand that people still disagree but at least do me the respect - as I respect your position - of reading my argument.
"If all of these debates are conducted around character and good faith, if you are not careful you end up a casualty of a debate that is all about that type of invective, you are then unable to have a proper debate about the difficulty of dealing with this issue."
Mr Blair said that despite the "terrible consequences" of the invasion - which saw Iraq plunged into a bloody sectarian civil war - the British-US military intervention had not been in vain.
"There may be people who believe that until I say I took the wrong decision, I am not properly sorry. I understand that. But I don't think this struggle was in vain in the end," he said..
"What we did in removing Saddam had terrible consequences which we didn't foresee - and I understand all the criticisms - but when I look at it today I think still that we moved with where the grain of the future is going to be in these countries and this region."
He denied that he had not challenged the intelligence reports more rigorously because he wanted to believe what they were telling him about Saddam's supposed WMD in order to justify going to war.
"I relied on the assessments that were given to me, but I think its fair to say - certainly given our experience - it would have been far better to have challenged them more clearly," he said.
"It wasn't that I wanted to believe it. I did believe it and one of the reasons for that was because Saddam Hussein had used these weapons against his own people."
Mr Blair said he accepted the report's finding that it would have been better if the cabinet had been given attorney general Lord Goldsmith's written advice on the legality of the conflict rather than having to rely on an oral briefing.
He added however: "I personally don't know what difference that would have made since he was there around the table".
Following strong criticisms in the report about the inadequacy of the military equipment - such as the lightly protected Snatch Land Rovers - Mr Blair insisted the generals had had all the resources they asked for.
"I don't recall a single occasion on which we were asked for more resources, more equipment that we didn't say 'yes'. I can't be in charge of the actual equipment that is needed," he said.
"Right at the outset, what I said - and Gordon Brown said the same - is 'There is no resource limitation. If you tell us what you need you will have the resources'. But obviously I can't say what is the right type of equipment to use on the battlefield."
Following the publication of the bombshell report, Mr Blair has been put on notice by families of dead servicemen that he may face legal action over what flowed from his decision eight months before the invasion to tell US president George Bush "I will be with you whatever".
Meanwhile, shadow Commons leader Paul Flynn said the Iraq Inquiry's findings amounted to an "utter condemnation" of Mr Blair's "terrible" decision to commit British troops to the US-led invasion, and prosecution of the former statesman should be given "serious consideration".
Former Scottish first minister Alex Salmond said he would like to see Mr Blair investigated by the International Criminal Court (ICC) for a crime of aggression and face parliamentary action to stop him holding public office again.
The long-delayed Chilcot Report insisted Saddam posed "no imminent threat" at the time of the invasion, and the war was unleashed on the basis of "flawed" intelligence.
And in a withering assessment of its aftermath, the probe found the military intervention ended six years later "a very long way from success", with the "humiliating" spectacle of UK troops in Basra making deals with local militia who had been attacking them.
Britain's ambassador to the UN at the time of the invasion has said the UK was "pushed" into entering military action too early by the US.
Sir Jeremy Greenstock told the BBC that Mr Blair had wanted a UN resolution backing military intervention in Iraq, but senior US officials thought it was a "waste of time".
"I felt that at the time, the British felt it at the time, I think the prime minister felt it at the time, that the Americans pushed us into going into military action too early," he said.
The US State Department said it would not respond to the report's findings as its focus is on tackling the issues present in the Middle East today.
"We are not interested in re-litigating the decisions that lead to the Iraq war in 2003 ... we are not going to go through it [the report], we are not going to examine it, we are not going to try to make an analysis of it or make judgment of the findings one way or another. Our focus is on the challenges we have in Iraq and Syria right now," a spokesman said.
"I believe that UK officials are taking it seriously and I am going to let them speak to it ... but that's where our focus is right now, not on doing the forensics on decisions that were made 13 years ago."
Giving evidence to the House of Commons Foreign Affairs Committee, Foreign Secretary Philip Hammond said that changes to decision-making processes introduced under David Cameron made it less likely that the shortcomings identified by the Chilcot Report would be repeated.
He cited Mr Cameron's creation of the National Security Council, in which military and intelligence chiefs can speak directly to political leaders.
"It is most unlikely that the same kind of failures could occur, given the structures we now have in place," said the Foreign Secretary.
Mr Hammond resisted pressure from Conservative MP John Baron - a long-standing critic of the Iraq War - to declare on behalf of the Government that the military action had been a mistake.
The Foreign Secretary said: "The key lesson I draw from (the Chilcot Report) is about failures of process all the way down the line.
"These are lessons we can very clearly draw and take corrective action to ensure these kinds of failure of process can't happen in the future."
Mr Hammond told the committee it was now widely accepted that it was a mistake to remove members of Saddam Hussein's Ba'ath Party from positions of power and responsibility following the conflict. Many Ba'athist military officers were now in senior positions within the fighting forces of the Islamic State terror group, he pointed out.
As a result of the experience in Iraq, international powers were approaching the issue of reconstructing Syria after its current civil war with "an appropriate degree of humility", he said.
"Maybe it was too great an ambition to try to simply dismantle a quite sophisticated country with a long-established civilisation, traditions and cultures of its own and recreate a sort of mid-Atlantic construct of what governance should look like, often going against the grain of local culture and local tradition," said Mr Hammond.
"What is being said about Syria by everybody is that we need to approach the post-conflict situation in Syria with a much greater degree of realism, recognising the limits of what is achievable, seeking to move Syria in the right direction.
"But I think nobody really thinks that in one bound we should turn Syria into a European-style democracy overnight. That's not a realistic or perhaps even a desirable outcome.
"Where we should focus our attention is on trying to create a Syria post-conflict that has a government acceptable to the overwhelming majority of its population."