When Saddam Hussein warned in January 2003 that a modern day version of Hulagu, the grandson of Genghis Khan who sacked Baghdad in 1258, was approaching, the comment was taken as the last howl of a flailing despot.
Three months later Saddam was on the run and the looting of Iraq was under way. A human tidal wave swept through the Oberoi Hotel on the banks of the Tigris in Mosul to remove every fixture. The ministries in Baghdad were stripped of box files and records. The contents of an artillery factory at Al Walid airbase, which lies close to the border with Jordan, was freighted lock and stock across an Iranian border point from Diyala province.
The regional implications of the fall of Saddam were all-encompassing. As Saddam had stated, the fall of Baghdad would unleash ruinous forces of historic proportions.
Some states, notably Iran, were ready to join the scramble. Others such as Turkey were forced into a defensive crouch that continues to this day. Saudi Arabia built a wall along the border as a cordon sanitaire. Only in recent months has Saudi Arabia reversed its approach, and is now offering a strategic partnership to Baghdad.
Adel Al Jubeir, the Saudi Arabian foreign minister, explained the policy as one designed to ensure that Iraq was not left to align with Iran by default. "We want to co-ordinate with Iraq on all levels, we want to invest in Iraq and its needs to rebuild after a difficult period of time," he said. "We want to be their partners and put the relationship on a high strategic level. Iran wants to dominate Iraq so it has a different agenda."
Rory Stewart, a British government minister who worked in Iraq after the invasion, said that the Iranian influence was palpable from the very start. "In the province where I was based, which is just on the outskirts of Basra, we had 52 political parties that suddenly emerged in about two weeks," he recalled last week.
"To one of them I said 'How many members have you got' and the man said 'I've 1,027 members'. I said 'how do you know the number' and he said 'because I've given them all Kalashnikovs and we've just come across the border from Iran'."
The driving rationale for the Iraq campaign was that the people who had suffered so much under dictatorship would embrace the conquest and thus align under a pro-Western democratic government. Tim Cross, a British general who commanded troops in Iraq, has called that idea "a misconceived -- even naive -- hope that Iraqi people would unite under their liberators, that they would easily and rapidly put behind them decades of distrust and internecine warfare to provide a stable and working democracy".
Javier Solana, a former EU foreign policy representative and opponent of the war, sees not just the conflict but the grievances surrounding its botched execution as the source of the subsequent troubles for the coalition. "While the 2003 invasion was a profoundly misguided policy, both in form and in substance, the chaos that consumed Iraq and the rest of the region stem from additional mistakes made by US policymakers after Saddam had been removed from power," he wrote on Project Syndicate.
"One of the most important lessons of the past 15 years is that military interventions aimed at regime change will almost always lead to disaster, especially in the absence of a sensible plan for what comes next. The Iraq War showed that the cost of unilaterally forsaking diplomatic channels can be enormous."
For Emile Hokayem, a researcher at the International Institute for Strategic Studies, the events of 2003 and the later Syrian conflict have dramatically altered the region, perhaps for good.
"The US invasion of Iraq and the resulting civil war, followed by the Syrian civil war, have fundamentally upended the regional balance and reshaped relationships throughout the Middle East," he said.
"The weakening of the US-led order has started under Bush out of hubris, continued under Obama out of desired entrenchment and accelerated under Trump out of disarray. This means that regional and local actors are rushing to redefine their relations and position themselves.
"Iran's rise was not inevitable but it was undeniably well positioned to take advantage of the turmoil in Iraq and Syria. Iran's asymmetric strategies are backed by competence and capability developed over four decades."
This, he said, gave Iran "a considerable head start over its regional competitors" in taking advantage of the chaos that ensued in the wake of Saddam's fall.