(DEFENCE SECURITY ASIA) — US forces are completing their withdrawal from Iraq by September 30, 2026, closing the remaining military footprint of a campaign that began with the 2003 invasion and returned in 2014 to fight the Islamic State. 

The departure fulfils a transition agreed by Washington and Baghdad in 2024, but its timing amid the US–Iran conflict makes the central question more urgent: who will supply the intelligence, logistics and political restraint previously associated with American forces?

The last personnel had been concentrated around Erbil in the Kurdistan Region after withdrawals from federal Iraq, turning the northern facilities into the final logistical link between the Iraq mission and counter-ISIS operations connected to Syria.

A formal deadline does not establish that every handover occurred at the same moment, because Iraqi accounts placed the departure of combat and logistical personnel earlier, while the remaining facilities and personnel were scheduled to close by September 30.

For Baghdad, the withdrawal is a sovereignty milestone; for Washington, it is the end of a large military presence and the intended start of a bilateral relationship with a smaller security footprint on Iraqi soil.

Iranian officials and allied Iraqi factions have presented the exit as a strategic victory, although the absence of US troops does not by itself establish that Tehran can direct Iraqi government policy or every armed group. 

Amir Hayat Moqaddam, deputy chairman of Iran’s parliamentary National Security Commission, said Iran “welcomes the withdrawal,” framing the American departure as a step toward regional security under terms that Washington and many Iraqi factions would contest.

Abu Mojtaba al-Yasiri, a commander associated with the Islamic Resistance in Iraq, called it “a historic victory,” a political claim whose operational significance depends on whether armed factions can expand their influence after the coalition leaves.

The immediate military test lies in Iraq’s ability to replace coalition intelligence, surveillance, reconnaissance and logistical support while preventing ISIS cells from exploiting gaps between federal forces, Kurdish units and security agencies.

A second test concerns state control of weapons, because militia missile and drone capabilities can threaten Iraqi facilities and neighbouring states even when the organisations holding them participate in Iraq’s political and security structures.

Kurdistan Regional Government Prime Minister Masrur Barzani has warned that “the threat is real,” reflecting northern concerns about exposure to ISIS activity and attacks as American intelligence and support assets leave the region.

The exit therefore changes more than a troop count: it removes an operational node, alters Baghdad’s bargaining position with armed factions and forces regional governments to reassess how Iraq’s territory might be used during the wider US–Iran confrontation.

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From Invasion to Exit: What the US Footprint Became

The American military presence began with the March 2003 invasion from Kuwait, when roughly 90,000 to 130,000 US ground troops entered Iraq; Baghdad fell in April, but removing the government did not settle the ensuing security contest.

Insurgency and sectarian violence drove the force well beyond its initial invasion posture, requiring extensive bases, supply lines and counterinsurgency operations that tied American combat power to the daily protection of routes, installations and Iraqi partners.

At the 2007 surge, roughly 160,000 to 170,000 US troops were in Iraq, illustrating the scale required for a ground campaign against insurgent networks compared with the few hundred personnel present in the final months.

The 2008 Status of Forces Agreement set a deadline for departure, and the formal end of combat operations in 2010 shifted remaining forces toward advising Iraqi units before the last combat formations left in December 2011.

That first withdrawal did not end the security relationship, because a small embassy protection and security cooperation presence remained, while the later collapse of Iraqi defences against ISIS demonstrated how quickly an external advisory requirement could return.

After ISIS captured Mosul and extensive Iraqi territory in 2014, Baghdad requested American assistance, bringing US personnel back under Operation Inherent Resolve to provide airstrikes, intelligence, training and logistical support to the counteroffensive.

The returning force grew from about 2,000 personnel in late 2014 to approximately 5,000 during the campaign to recapture territory, a smaller formation whose effect depended heavily on Iraqi ground forces and coalition enabling capabilities.

Once ISIS lost its territorial caliphate, Washington formally ended the US combat role in Iraq in December 2021 and retained roughly 2,500 troops for advice and assistance, with positions including Al Asad and sites near Baghdad and Erbil.

The September 2024 transition plan provided for the coalition military mission in federal Iraq to end first, while continued support connected to operations against ISIS in Syria remained subject to conditions through September 2026. 

The progression from occupation to advisory mission and final withdrawal matters operationally because the last contingent represented less combat mass than an enabling network of access, communications, intelligence support and connections to regional forces.

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Erbil, Syria and the Logistics Footprint

Following the drawdown from federal Iraq, the remaining American presence centred on the Kurdistan Region, where facilities around Erbil supported a narrower mission linked to counter-ISIS activity and the continued movement of personnel and equipment.

The handover of Al Asad and other federal Iraqi facilities reduced Washington’s ability to sustain operations from dispersed Iraqi locations, concentrating the final phase around fewer northern access points and increasing the importance of each remaining site.

Erbil’s value extended beyond the number of troops stationed there, because a base that handles transport, communications, intelligence and force protection can sustain operations across a much wider area than its visible personnel complement suggests.

Removing that infrastructure changes the practical distance between US decision-makers and events inside Iraq, potentially increasing the time needed to develop intelligence, coordinate with Iraqi counterparts or reposition support from neighbouring countries.

The planned relocation of personnel to Jordan and other regional sites preserves options for American forces, but operating from outside Iraq changes transit requirements, access arrangements and the degree of routine contact with Iraqi units.

The 2024 plan explicitly connected its later phase to preventing an ISIS return from northeast Syria, making the Iraq–Syria interface a central measure of whether the new force posture can sustain pressure across the border. 

A departure from Iraqi facilities does not necessarily terminate intelligence exchanges or bilateral cooperation, although the effectiveness of either arrangement will depend on permissions, secure communications and Iraqi capacity to act on information independently.

For Kurdish authorities, the lost footprint includes the practical support associated with US drones, logistics and intelligence, while the threat assessment also involves attacks on regional sites that had no direct American connection.

Kurdish commander Sirwan Barzani has reported greater ISIS sleeper-cell movement since the withdrawal timeline became public, but that observation alone cannot determine whether the movement reflects a lasting organisational resurgence or a temporary response.

The northern transition will therefore be judged by observable outcomes: the speed of cross-border coordination, protection of exposed facilities and the ability of Iraqi and Kurdish forces to locate and disrupt cells without resident US support.

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ISIS Cells and the Gaps Iraqi Forces Must Cover

ISIS no longer holds the territorial caliphate that prompted the 2014 American return, yet Iraqi and Kurdish warnings concern smaller cells whose mobility and concealment make intelligence coverage more decisive than large-scale conventional firepower.

Areas cited as concerns include the Hamrin Mountains, Kirkuk, Tal Afar and approaches around Mosul, where terrain, jurisdictional boundaries and dispersed populations can complicate persistent surveillance and rapid coordination between security forces.

Coalition intelligence, surveillance and reconnaissance helped identify targets and monitor patterns of movement; replacing those functions requires more than aircraft, because analysts, communications links, maintenance and trained units must operate together.

Logistical assistance also affects operational tempo, since a force that can identify a cell but cannot promptly move personnel, sustain an operation or share reliable information may lose the opportunity to disrupt it.

Iraqi forces have far greater responsibility and experience than they possessed during the ISIS territorial offensive, but the relevant question is whether their current capabilities cover the particular functions the departing coalition supplied.

Security officials have described sleeper-cell activity and a disrupted plot involving suicide attacks timed to the pullout, claims that warrant continued scrutiny because neither an announced plot nor increased movement proves an imminent nationwide ISIS revival.

The comparison with 2011 is a warning about possible pathways, not a prediction: ISIS’s later expansion followed several political and military developments, and the conditions after the 2026 withdrawal must be assessed on their own evidence.

Any decline in counter-ISIS pressure could have consequences beyond Iraq if cells exploit routes toward Syria, especially where the coalition’s previous mission treated the two theatres as connected rather than as separate national problems.

Conversely, effective Iraqi and Kurdish coordination could limit the strategic effect of the American departure, demonstrating that sovereign forces can maintain surveillance, response and border security without a standing coalition footprint.

The first months after withdrawal should therefore be measured through disrupted networks, attack patterns and response times, rather than by claims from either advocates or critics that the troop departure alone has settled the ISIS threat.

Iran-Aligned Militias and Baghdad’s Monopoly on Force

The departure also removes a visible US military counterweight from Iraqi territory while Iran-aligned factions retain political networks and armed capabilities, creating an immediate test of whether Baghdad can enforce decisions across the security system.

Militia leaders have framed the withdrawal as vindication, but influence over Iraq’s future will be determined by command relationships, control of missiles and drones, and the government’s willingness and ability to limit unauthorised attacks.

Prime Minister Ali al-Zaidi has linked the end of the foreign presence to bringing weapons under exclusive state control, describing that objective as “a necessity” while moving from an immediate disarmament expectation toward a phased timetable.

His stated approach begins with a 90-day halt in attacks and envisages weapons handovers by June 30, 2027, with individual fighters entering state structures and groups still armed after the deadline treated as unlawful.

That sequence creates an enforcement problem: a ceasefire may lower immediate violence, but meaningful disarmament requires inventories, verified handovers and an agreed chain of command that can prevent weapons from reappearing under another factional label.

Hardline groups including Kata’ib Hezbollah and Harakat Hezbollah al-Nujaba have resisted immediate disarmament and attached conditions involving foreign forces, air defence and border control, leaving a gap between the government’s timetable and factional commitments.

Some other factions have indicated greater willingness to cooperate, so treating Iraq’s armed groups as a single actor would obscure the different incentives Baghdad must address while avoiding an internal confrontation during a regional war.

The risk to neighbouring states is material because armed groups with missiles and drones can use Iraqi territory to generate cross-border effects, even when Baghdad seeks diplomatic distance from their decisions and operations.

Washington’s accusation that Iran-backed groups attack at Tehran’s direction is consequential but should not be applied indiscriminately without evidence for particular incidents, given the varying command arrangements and interests among Iraqi factions.

Baghdad’s strategic success will depend less on the symbolism of September 30 than on whether it can prevent parallel armed structures from setting external security policy through attacks that expose Iraq to retaliation.

A Sovereignty Milestone with Regional Consequences

Iraq’s government can plausibly claim greater formal sovereignty after the withdrawal, yet sovereignty in operational terms also requires control over airspace, borders, intelligence decisions and armed groups capable of acting without state orders.

Sunni figures have warned that the security transition could leave exposed communities if federal forces cannot contain ISIS cells, while Kurdish leaders have emphasised the loss of American support and the vulnerability of northern facilities.

Abdulrahman al-Zobaie in Fallujah said Iraq was “still not fully ready to take over the security file,” expressing a concern about capacity that should be tested against performance rather than treated as proof of an inevitable vacuum.

Atheel Al Nujaifi has likewise warned that ISIS cells remain active, framing counterterrorism as an Iraqi interest that cannot be subordinated to the contest between Washington, Tehran and their respective regional partners.

The human cost sharpens the significance of the transition: approximately 4,500 American service members died across Iraq-related operations, although casualty categories covering Operation Inherent Resolve also include deaths outside Iraqi territory.

Operation Iraqi Freedom accounted for 4,418 US military deaths and about 31,994 wounded, while Operation New Dawn added roughly 74 deaths; these figures describe different operational periods and should not be conflated with Iraq-only losses after 2014.

Documented Iraqi civilian deaths from violence since 2003 are estimated in the hundreds of thousands, but incident records and broader estimates use different methods, leaving substantial uncertainty over the full direct and indirect toll.

The withdrawal cannot reverse those losses, yet it makes the durability of Iraq’s institutions the decisive measure of what follows more than two decades of foreign intervention, counterinsurgency, militia competition and anti-ISIS operations.

For the United States, regional basing and bilateral ties may preserve influence without resident troops, but that approach depends on Iraqi consent and offers fewer routine opportunities to shape events at the point of contact.

For Iraq, Iran and neighbouring states, September 30 begins a practical test of force posture and political authority: whether Baghdad can secure its territory, contain ISIS and prevent armed factions from turning Iraqi soil into a regional launch point.