US forces are set to pull out from their last bases in Iraq, leaving the country where 4,500 of their comrades died over more than 20 years of war.
The departure of American troops will be celebrated as a victory by Iran and its allies, who now have deep influence in the country.
Iraqi security experts have warned that the withdrawal could give Tehran and its allies free rein while also risking a comeback from the Islamic State terror group.
The move was agreed in 2024 under President Joe Biden and carried out by President Donald Trump's administration, even as it wages war against Iran.
"Iran stands to benefit strategically from the coalition's departure because it removes a military presence that for years acted as a counterweight to Tehran's influence in Iraq," said Jasim al-Bahadli, an Iraqi security analyst.
He warned that the pro-Iranian militia groups would not only portray the departure as a victory for their movement, but also "seek to translate that momentum into greater influence over security and political decision-making".
Coalition forces invaded Iraq in 2003 and went on to occupy the country and fight a years-long insurgency before withdrawing in 2011.
The UK lost a total of 179 servicemen and women in the campaign.
American troops returned less than three years later to help Iraqi forces defeat ISIS in a major war from 2014 to 2017.
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While the eventual departure of US forces is broadly popular among Iraqis, some fear the move is premature.
"We believe Iraq is still not fully ready to take over the security file at this time," Abdulrahman al-Zobaie, a Sunni tribal leader in Fallujah, once a bastion of anti-American resistance, said.
"All Iraqis aspire to full sovereignty, and no Iraqi would dispute that. But I believe that the (US-led coalition) leaving in this way and creating a vacuum is what all Iraqis fear."
(c) Sky News 2026: US forces to leave last bases in Iraq despite fears Iran will exploit withdrawal
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