There was an awful lot to take in from Sir John Chilcot’s half hour statement, and there will be more to take in from the two million plus words he published when people get round to reading it, and the torrent of reaction.

There were many criticisms, and I know Tony Blair will respond to them later today. I am sure, too, that he will take responsibility for the decisions he took, and stand up for the soldiers, intelligence officers, civil servants and others who are criticised. One thing I know about Tony Blair is that he stands up for those who work for him, when they are acting on decisions he has made.

I hope people will forgive me, though this is by no means the biggest point in the report, if I begin this blog by focusing on the part of the Iraq narrative with which I have been most associated, and which was one of the factors behind my decision to leave Downing Street in the autumn of 2003. I did not receive a Maxwellisation letter, and so I am assuming I am not criticised within the report. That is four inquiries now which have cleared me of wrongdoing with regard to the WMD dossier presented to Parliament in 2002, and I hope that the allegations we have faced for years – of lying and deceit to persuade a reluctant Parliament and country to go to war, or of having an underhand strategy regarding the respected weapons expert David Kelly – are laid to rest.

The truth was – and remains, confirmed today – that the so called sexing up of intelligence never happened. The Today programme report that said it had should never have been broadcast, and the BBC should have properly investigated our complaint rather than dismissed it out of hand because it came from Downing Street. Had they done so, David Kelly would almost certainly be alive today, and no attempt by the media to say it was ‘six of one, half a dozen of the other’ will ever move me from that view, or fully erase the anger I feel at their dishonesty. Sorry, but I feel I have to say that.

I hope too that one of the main conspiracy theories peddled in the main by former US Ambassador Sir Christopher Meyer, that Tony Blair did a secret deal with George Bush at Crawford, Texas, in April 2002, is also laid to rest. There was no secret deal, there was no lying, there was no deceit, there was no ‘sexing up’ of the intelligence. What there was was a decision, a set of decisions, which ultimately had to be made by the Prime Minister.

Though Sir John did not say so in so many words, it was clear from his presentation that he believed the Iraq War was a big mistake. He set out many reasons why he believed so. But his report does accept that ultimately leaders have to make decisions, and especially the tough ones.

I listened to his statement on Radio Five Live, from Barcelona, where I have been at a conference. The immediate response of Peter Allen’s experts and correspondents was drowned out by the chanting of protesters in the background ‘Tony Blair … war criminal,’ and I could hear a succession of speakers saying what they had clearly planned to say before Chilcot had said or published a word.

As we have seen in the debate surrounding the EU referendum, we live in a post-factual, post-reason age where many parts of the media, and many people, tend to find the facts that fit the argument they already believe, the pieces of evidence that fit the world view they already hold, the opinions that match their own. This is a phenomenon born in the fusion of news and comment in most newspapers as they adapted to TV, developed in the sound and fury of 24/7 TV news, and ventilated by the howling rage of social media. People say they want the full truth to emerge, but is that really so? Or do they in fact only want the truth in so far as they already believe it to be, like the screaming protesters outside the QE2?

So when the latest murderous ISIS attack in Baghdad happens, a few days ago, with Chilcot looming, the BBC’s Middle East correspondent, Jeremy Bowen, cannot resist adding two and two together and making whatever the number of deaths happens to be. ‘Sectarian war started in the chaos and violence that was unleashed by the American and British invasion of Iraq in 2003,’ he said. ‘Plenty of Iraqis have already made up their minds: that the invasion and occupation pushed them into an agony without an end.’ Plenty of Iraqis, and not merely Kurds and Shias, also remain glad that Saddam Hussein is no more. We just don’t see or hear them too often on British TV stations. Sir John was clear that the government’s objectives were not met. With regard to the aftermath, short, medium and long-term, that may be so, though Iraq is at least a democracy and one that is fighting terrorism. But the fall of Saddam, when the invasion took place, was a core objective, and the world is a better place without him and his sons in charge of their country.

Sir John acknowledged that war may have been necessary at some point, but argued that the timetable was rushed to suit US interests. It is true that the Americans were keen on action. It is also true, as he acknowledged, that Tony Blair did have some influence in getting Bush to go down the UN route.

Here is where I find the most extreme criticisms of Mr Blair from those who hate him most difficult to accept.

I was one of the few people who saw the process of his making the decision close up, virtually round the clock, around the world. Far from seeing someone hellbent on war, I saw someone doing all he could to avoid it. Far from seeing someone undermine the UN, I saw him trying his hardest to make it work. Far from seeing someone cavalier about the consequences of war, I saw someone who agonised about them, and I know he still does, as do all who were there, part of his team.

He was of course bombarded by views, from friend and foe. He was acutely aware of protest. He was aware that much could go wrong. He was aware lives would be lost. He was conscious of the possibility of damage to our relationship with the US if we didn’t go with them, and damage to the relationship with other allies if we did.

But here is the difference between him and other ministers and MPs, him and advisors, him and commentators, him and the public who three times elected him, including after the fall of Saddam. He had to decide. One way or the other. With the US or not. Topple Saddam or leave him. Knowing that either way there were consequences which were hard to foresee.

We elect leaders to make the toughest calls. Amid all the talk of learning lessons I fear we have already learned some wrong ones. Leaders in democracies have learned that if you do the really difficult, unpopular thing, it can be hung around your neck forever. ‘Look at Tony Blair,’ they say, ‘in so many ways a great Prime Minister yet with so many people refusing to see him as the author of anything but chaos in the Middle East.’ One, it is over simplifying things to say he is the author of that chaos, as I explain later, but someone even now, though out of power, trying harder than many of those in power to do something about it. Two, he made many changes to our country and to the wider world which cannot be erased from the national consciousness because of one hugely controversial issue.

So I saw the care he took over the decisions. I have seen the agonies it has caused him many times since and will do till his dying day. The deaths of soldiers weigh heavily on him, as do the deaths of Iraqi civilians. He knows there are things he should apologise for. But one thing he will never apologise for is standing up to one of the worst, most fascist dictators the world has ever known. Nor should he. For all the faults in Iraq today, a world without Saddam and his sons in charge of Iraq is a better and safer world, and those who gave their lives to make it happen did not, in my view, die in vain.

He accepts Iraq and the region have not advanced as we had hoped, but I wish more could be heard from those – they exist – who will speak up for the democracy that has developed, the fight against terrorism the government is leading, and the progress, albeit too slow, that has been made; I also wish the Blair haters were able to see things from his perspective, as the man who had to make the decision, in a way that we can see things from theirs.

Some of the main criticisms appear to be related to the aftermath, and many of these seem to me to be justified. We assumed, wrongly, that the Americans would be as interested in the aftermath as they were in the military operation to topple Saddam. They were the main player and we, a junior partner in a huge international alliance, did not press them hard enough.

In some ways we were prepared for the wrong things. Take WMD. I can remember accompanying Tony Blair to a pre-war briefing at the Ministry of Defence, where he was being briefed on the equipment our troops would rely on in the event of Saddam using chemical and biological weapons against them. It was one of those moments when your heart leaps to your throat. It felt horribly real. It was a moment of real fear and Tony Blair pressed to make sure that troops who faced such a threat had the capacity to be able to deal with it. I cite that for two reasons – to emphasise that we sincerely believed the intelligence on WMD, and we believed Saddam might use them because he had done so when threatened in the past; and also to debunk the idea that Tony Blair made the decisions he did in a cavalier or uncaring way. To the conspiracy theorists who say he did it for Bush, he did it for oil, he did it because of some weird Messiah complex, I say do you really think any British Prime Minister would put troops in the horrific situations that were outlined to us unless he believed the threat was real, and one which, unless we showed we were serious about dealing with WMD, would one day pose a risk to all of us?

We prepared too for a long and bloody battle with Saddam’s Republican Guard, but in the event the military battle to topple him was won more easily than expected. The welcome from the people seemed real. That may have bred complacency. Haters of Saddam as they were, we thought the Iranians would welcome his fall. Instead, perhaps obviously but it didn’t seem so at the time, they exploited it. More widely, we seriously underestimated the potential reaction of different powers and forces within the region, and their capacity for the chaos which they unleashed. Sir John suggests the government should have seen this coming.

But here too the simplicity of the debate in the UK about the post-Saddam Middle East must be challenged. To say the Iraq invasion ‘created ISIS’, as many commentators do, is on a par with saying the war in Afghanistan ‘created Al Qaida’ when in fact that war came as a consequence of 9/11 not its cause.

A bit of history. Al Qaida in Iraq, the forerunner of ISIS, was formed by the Jordanian Abu Musab al-Zarqawi, to fight Western forces in Iraq. But it rapidly moved on to trying to kill as many Shia as possible, and provoked them by destroying their holy sites. It was over that approach that its leader fell out with the leadership of Al Qaida in 2005. But when we left in 2010 Al Qaida in Iraq was largely defeated by the ‘surge’ of mainly US troops, by the Anbar awakening, and by our special forces.

ISIS emerged as a force out of premature departure from Iraq without taking the steps needed to try to reconcile Sunni and Shia. It was fuelled in Iraq by Sunni anger at the sectarian policies of the Maliki government and the threat from Shia militias fighting their way north; and in Syria by resentment at the vicious behaviour of the Allawite regime of President Assad.

Here is where I find some of the criticisms of Tony Blair from the left most difficult to accept. He is called a war criminal for acting to remove a real war criminal like Saddam who had killed more Muslims than anyone on the planet and with a human rights record to match some of the most brutal dictators of all time. Yet those same people were and remain prepared to stand by and do nothing to deal with Assad, despite the Syria death toll now being far greater than that in Iraq. ‘Standing up, not standing by,’ is the current Labour Party slogan. Well, we have not stood up for the Syrian people. We have stood by and allowed a catastrophe to unfold, millions fleeing terror, Assad using barrel bombs and crossing the so-called ‘red line’ of chemical weapon use with seeming impunity. One of the reasons ISIS has grown so strong, and become such a threat in Europe, is because we in Europe have not been prepared to intervene to prevent the emergence of a failed state in Syria and northern Iraq, just as Afghanistan became the failed state from where Al Qaida could plan the attack on the twin towers.

Syria is where ISIS has truly thrived, thanks in large part to non-intervention. Libya – where there was partial intervention but even less follow through than in Iraq – is now a country in chaos and becoming an important base for ISIS. Of these countries only Iraq has a legitimate Government fighting terrorism.

And those who say the UK action in Iraq put us in the front of the queue for attack should note that ISIS has been and remains indiscriminate. France was our most vocal critic over the war in Iraq, yet has been a greater victim of ISIS than we and others who backed the US-led action. Belgium played no part in the war, but it too has been struck by ISIS.

Other areas of criticism from Chilcot centre on the process surrounding the Attorney General’s advice, and the role of the UN. A brief word on both.

People often talk of the UN as though it were a court of law, able to adjudicate on difficult and complex issues. It is not. It is a collection of all the countries of the world with all their competing visions and interests. But particularly today, with Putin’s Russia one of the five permanent members of the Security Council, it is rarely a body on which full international agreement can be found on anything. The inquiry believes we had not exhausted all diplomatic efforts. Of course, we could have gone on talking. But the reality is that there came a point where France and Russia were never going to follow through on the logic of Resolution 1441, agreed unanimously including by them, which was yet another ‘final opportunity’ for Saddam to comply with the weapons inspectors, deliver on the many UNSCRs he was still defying, or face the consequences.

When negotiating that Resolution, everyone – including France and Russia – understood what it meant. Indeed opponents of the US-UK strategy had sought to insert the obligation to return to the UN for a specific mandate for military action and this was rejected. I remember Derry Irvine, Lord Chancellor, saying to a meeting of the Cabinet that we had tried so hard to get the second resolution that people assumed there could be no action without it. ‘But that is not the case.’

As for the messy process, I fear that was inevitable given the white hot political context, the fluid circumstances of the build up to war in so many countries, and the worries about leaks – which were real. People may be surprised that Cabinet ministers did not grill the Attorney General directly on his advice when they had the chance. But I think they were sensitive to the possible accusation of seeking to influence someone who is meant to be able to offer advice independently. And whatever the process I think he would have reached the decision he did. There are suggestions the advice should have been debated and even voted upon in Parliament. But the military need absolute clarity on the legal base for war. I can remember the Chief of Defence Staff, and the head of the Civil Service, asking for it in very blunt terms. People really need to think carefully before going down that route.

So no lies or deceit, contrary to what Jeremy Corbyn has just said. No secret deal with Bush. A messy process surrounding the legal advice and the role of the UN. Mistakes in intelligence but no improper interference with it. Bad planning for the aftermath. Many mistakes and shortcomings made alongside successes.

I am going to leave the final word in this piece to the constitutional expert, Professor Vernon Bogdanor. Last month he gave a long and thoughtful lecture on the Iraq war, at Gresham College in London. It was a calm and cold-headed analysis and merits careful reading. But I was particularly struck by his final paragraph.

‘Of course, with hindsight, all things might have been done differently, but as President Bush said, and on this I agree with him, “Hindsight is not a strategy. Everyone’s hindsight is better than the most acute foresight.” My conclusion,’ said Bogdanor, ‘is that there are no easy answers, that Bush and Blair were faced with an almost impossible dilemma, and that all of us should be very grateful that we were not in their shoes and did not have to make their difficult decisions.’

The Chilcot Inquiry panel knows a lot about foreign policy, and about government process. They have been through millions of documents and produced a huge and challenging piece of work. But ultimately, as they recognise, they have never actually had to make the decision they have been examining. Such decisions are the stuff of leadership, which may explain why David Cameron, whose statement I have just listened to as I finish this, seemed to be speaking with considerable sympathy and support for his predecessor. He knows how hard these decisions are. He also knows that there may well be times in the future where we have to put our armed forces in harm’s way once more.