There may be some who will deride the Chilcot report as a whitewash, because it does not contain tabloid-style indictments of Tony Blair or Jack Straw.
But in its very British, factual, understated way, its 2.6m words are a devastating critique of Blair and his government - of a failed and unnecessary war that cost countless and mostly civilian Iraqi lives, sent British soldiers to their deaths, destroyed any hope of stability in Iraq and made Britain more vulnerable to terrorism.
At a time when our national self-confidence is being sorely tested by the realisation we are a long way from having a detailed plan for how to thrive outside the EU, Chilcot is another shattering blow to our international reputation and our pride.
How to put this into context?
Well 60 years ago the Suez crisis engendered a deep sense of national shame, that scarred us and conditioned our politics for many years.
Our Iraq adventure, combined with our failure to prepare in detail for Brexit, may be as bad for us or worse.
Later today, Jeremy Corbyn will apologise for the misguided actions of a Labour government in taking the UK to war in March 2003. Tony Blair will again refuse to concede he made a terrible mistake.
In the circumstances of Labour's deep division between its leader Corbyn allied with its members on the one hand and Labour MPs on the other, Chilcot may in fact be the hammer that destroys the party in any recognisable form.
If you are feeling strong enough, let's go through Chilcot's critique that we were wrong to go to war when we did, and we were appallingly negligent in our failure to prepare for the aftermath of conflict.
Here are the main findings:
1) When we went to war in March 2003, "there was no imminent threat from Saddam Hussein.
2) "The strategy of containment could have been adapted and continued for some time"
3) The UK military role in Iraq "ended a very long way from success"
4) "The circumstances in which it was decided that there was a legal basis for UK military action were far from satisfactory"
5) By going to war the UK was "undermining the [UN] Security Council's authority", in that most members of the council were rightly unconvinced that peaceful options to disarm Iraq had been exhausted.
6) There was a grotesque and systematic absence of proper cabinet oversight of almost all the important Iraq decisions, with far too much power residing in Blair
7) Policy on Iraq was made on the basis of "flawed intelligence and assessments", which should have been challenged, such as that Iraq possessed significant stockpiles of weapons of mass destruction, the means to deliver them and the capability for further build up.
8) Blair was correctly warned "that military action [in Iraq] would increase the threat from Al Qaida to the UK and to UK interests" - which was at odds with his statement to MPs that the threat from Saddam's arsenal posed a clear danger to British citizens.
9) Blair's view that we had to stand shoulder to shoulder with the US is derided by Chilcot, who points out that the decision of France and Germany to oppose the war has not done significant damage to their respective relationships with the US.
10) Cabinet "did not discuss the military options or their implications"
11) Chilcot disagrees with Blair that "the difficulties encountered in Iraq after the invasion could not have been known in advance" - and says that "the risks of internal strife in Iraq, active Iranian pursuit of its interests, regional instability and Al Qaida activity in Iraq were each explicitly identified before the invasion"
12) "Ministers were aware of the inadequacy of US plans" to deliver stability in post-invasion Iraq.
13) Blair "did not establish clear ministerial oversight of UK planning and preparation" and "did not ensure that there was a flexible, realistic and fully resourced plan that integrated UK military and civilian contributions, and addressed the known risks".
14) The British government's preparations "failed to take account of the magnitude of the task of stabilising, administering and reconstructing Iraq, and of the responsibilities which were likely to fall to the UK".
15) "The scale of the UK effort in post-conflict Iraq never matched the scale of the challenge" and "Whitehall departments and their ministers failed to put collective weight behind the task".
16) The ministry of defence was "slow in responding to the threat from Improvised Explosive Devices" and "delays in providing adequate medium weight patrol vehicles should not have been tolerated".
17) UK defence resources were chronically overstretched by their deployment in both Afghanistan and Iraq.
18) It was "humiliating that the UK" made a bargain with Basra militias to end the targeting of our forces for the exchange of detainees.
The lessons of the tragic Iraq intervention are legion. Some have already been learned. Others the government will learn.
But for most readers of Chilcot there are two overwhelming emotions: national regret and national shame.