Eleven years on and American revenge against Iraq’s Sunnis is looking more disastrous by the day.
Saddam Hussein was a Sunni and in the mind of the victorious Bush neo-cons his defeat in 2003 meant his fellow Sunnis should also pay dearly.
For Donald Rumsfeld, Paul Bremer and the rest of them that had a purity to it.
So, not long after Saddam was swept from power, the policy of de-Baathification was imposed.
Sectarianism is another name for it.
(Saddam was many things, but not a bigot. He dispensed cruelty even-handedly and he was feared equally by Shia, Sunni, Kurd and Christian alike.)
Members of the Baath Party were almost exclusively Sunni, so their dismissal from the ranks of the police and army and from the corridors of political power meant the disenfranchisement of Iraq’s Sunnis, around 40 per cent of the country’s population.
Because they had a past they were told they had no future. They were turned away, defeated and resentful.
More than a decade later the dissent that lingers among Iraq’s Sunnis is the greatest strength on which ISIS can draw.
Isis are playing the role of liberators in Mosul, the mainly Sunni city they captured without a fight last week. They are putting the lights on, opening bazaars..
“No more Ali Babas in Mosul,” a lorry driver shouted to me as he headed back to the city on Sunday. What he meant was that as far as he was concerned the thieving police officers and soldiers from the Iraqi security forces had been routed and good riddance.
Residents who’ve stayed are saying the city is peaceful and that Isis fighters are being very kind.
But chilling photographs posted by Isis of civilian-clothed young men being marched off to execution underline the brutality of what’s going on here.
Those young men were security force members who had surrendered. Mainly Shia, Isis has shown them no mercy.
Iraq has broken up into three pieces, a Kurdish north, a Sunni centre and a Shia south, taking in Baghdad.
Broadly speaking the military forces in control of each area has the support of the locals.
Putting these pieces back together again, making them the country we knew as Iraq, looks almost impossible.
There is no political process to speak off. No negotiations are taking place that might bring a ceasefire.
Sectarian hatred has been re-kindled and it might be years before fighting between the three areas can be halted.