The UK is holding its breath, waiting for the results in the coming weeks of the long-delayed Chilcot enquiry into those events.
It is also agonising over whether to join the Americans and others in extending its bombing campaign  from Iraq to Syria against the militants of the self-styled Islamic State (IS), whose rise is widely seen as a consequence of the 2003 invasion and the ensuing upheavals.
Since the outset of the Syrian crisis in 2011, the Americans and their Western partners have been mesmerised by the chaos in Iraq as an object lesson for how not to deal with Syria.
That is the overriding reason why they have long tiptoed around the prospect of embroilment in the Syrian affair.
US President Barack Obama was elected specifically on a platform of ending such foreign adventures, not getting caught in yet another one.
It was only with extreme reluctance that he found himself drawn into the air campaigns against IS in both Iraq and Syria, with limited and cautious engagement of advisers and special forces on the ground.
It was all very different back in 2002 and 2003, when the neo-conservatives then in the ascendant in Washington were looking for any pretext to move against Iraq and topple Saddam Hussein, as part of a broader ambition to shape a "new Middle East".
Ahmed Chalabi, who had left Iraq in 1956, at that time headed the umbrella opposition grouping in exile called the Iraqi National Council (INC).
Viscerally dedicated to the overthrow of Saddam Hussein, Chalabi found himself point man for an opposition effort to persuade the Americans to invade and rid the country of the feared dictator, having despaired of other methods such as trying to engineer an internal coup.
He found himself knocking on an open door.
If he knowingly misled Washington with dodgy intelligence on Saddam's non-existent weapons of mass destruction and links with international terrorism, he knew that powerful American circles were willingly taking the bait without scrutiny as they prepared for their war of choice.
They were using him, and he was using them.
With the Chilcot conclusions looming, Tony Blair, who led the UK into the Iraq war alongside the Americans, came out recently in a CNN interview with a qualified apology for the fact that the intelligence on which the invasion was based was false and that insufficient thought had been given to what should happen next.
But Chalabi entertained no such misgivings. In conversations late last year, he was still exultant at his own role in triggering the invasion which unseated Saddam Hussein. For him, that was the overarching goal that justified any possible means.
But it was not just the removal of the dictator that plunged Iraq into the chaos which has continued to shake and fragment the country ever since.
In the months that followed, every political and security structure holding the country together was dismantled, including the all-pervasive Baath Party (a process in which Ahmed Chalabi played a role), the army and the intelligence services.
Thousands of highly experienced officers and officials from Saddam Hussein's minority Sunni community were sent home with a burning grudge, setting the scene for the subsequent Sunni-based insurgency, sectarian fragmentation and blood-letting, and the eventual emergence of IS.
IS began in Iraq and later spread to Syria, where it could exploit the chaos and vacuums caused by the civil war to entrench and grow, eventually erupting back into Iraq with the storming of Mosul last year.
Now it is firmly entrenched in both countries, and the prospects for pulling both of them back together as unitary states are daunting, given the degree of fragmentation in both.
That is the spectre haunting the West, as it ponders how to deal with a crisis that has sent millions of refugees into neighbouring countries, and hundreds of thousands flooding into Europe.
Doing nothing may increasingly not be an option. But the fate of Iraq since 2003 underscores the potentially disastrous dangers of ill-conceived meddling.
The unexpected death of Ahmed Chalabi has highlighted the burning issues still haunting the UK and the West, long after the key role he played in manipulating the US-led invasion and overthrow of Saddam Hussein in 2003.