All political leaders are judged by history and Tony Blair knows that whatever he achieved as prime minister, his legacy will be forever tainted by his flawed decision to invade Iraq.
It is not just history making that judgment. It is Sir John Chilcot, who set out his devastating findings yesterday in a long-awaited, two million-word report.
It is those who suffered so much in Iraq, the tens of thousands of civilians who died and are largely forgotten.
And it is the families of the 179 British military personnel who lost their lives in a discredited war which was based on a false premise with poor preparation and no plan beyond toppling Saddam Hussein.
Anyone who signs up for the armed forces knows they may be asked to put their lives on the line for their country but what many relatives find unforgivable is not just the reason for this invasion but the fact that soldiers were sent to war so badly equipped, a failure that contributed to their deaths in some instances.
The Chilcot report is a major endeavour which will take some time to digest. However, the main conclusions provide a damning indictment of Mr Blair and his government at the time.
The main finding was that the UK chose to join the invasion of Iraq before peaceful options for disarmament had been exhausted.
``Military action at that time was not a last resort,'' said the report.
That is a very difficult finding for people to swallow. War should always be the option of last resort and it is shocking that the gravest decision a leader would ever have to make was taken before all other avenues were explored.
We already know that the supposed threat from weapons of mass destruction simply did not exist.
But despite all the clear warnings, the government completely underestimated the consequences of invasion.
Mr Blair, in a passionate defence of his actions, refused to accept that the violence, terror and instability which has gripped the region in recent years was a direct result of the intervention he ordered in 2003.
He did express ``sorrow, regret and apology'' for the failures in Iraq but stuck to the line that it was the right thing to do and the world was a better place without Saddam Hussein.
There is no doubt the Iraqi dictator was a brutal, cruel and dangerous tyrant who carried out unspeakable crimes against his own people.
But this alone was not enough to justify going to war.
While Tony Blair will fiercely defend his record, he will know that public opinion will take a harsher view of his fateful, far-reaching and ultimately catastrophic decision to invade Iraq.
