Introduction
On Sept. 27, 2024, the United States and Iraq announced a two-phase transition plan for the gradual drawdown of coalition operations in Iraq. U.S. troops, however, will remain in the country to support the mission against the Islamic State in northeastern Syria and in Iraq. About 2,500 coalition troops are present in Iraq, with about 2,000 U.S. troops in Syria. It is expected that U.S. troops in Iraq will gradually move from existing posts in Baghdad to Iraq’s Kurdistan Region, enhancing the strategic influence of the Kurdistan Regional Government (KRG) as a logistics and operations hub for both Iraq and Syria. However, after the Assad regime’s fall in Syria in December and the potential for cross-border ISIS activity, Iraq now prefers to keep coalition forces at the Ain al-Assad base in Western Iraq to counter threats from the Syrian border. This shift in posture also reflects Iraqi concerns that the new authorities in Syria were once affiliated with al Qaeda and had fought in Iraq.
In the drawdown’s first phase, which is set to conclude by September 2025, the coalition is scheduled to conclude its military leadership and transition to bilateral security partnerships. In the second phase, which will continue through at least September 2026, former coalition members will continue operations against ISIS in northeastern Syria from bases in Iraq in consultation with the U.S., the KRG, and Iraq’s federal government. After this, troops will most likely stay as part of bilateral security agreements with the Iraqi federal government. In its quarterly report to the U.S. Congress on Feb. 19, the Pentagon’s inspector general reports that the U.S.-led coalition intends to expand its assets and multinational personnel at Erbil Air Base in the Kurdistan Region, while transferring control of Ain al-Assad base to Baghdad.
However, the developments in Syria might further slow the transition in Iraq, unless the administration of President Donald Trump decides to withdraw from Syria, as it briefly did in 2019. A U.S. troop withdrawal there could lead to a Turkish offensive against the Kurdish-led Syrian Democratic Forces (SDF), creating a security vacuum that could be exploited by ISIS, especially in areas like Deir ez-Zor. NBC reported Trump has shown interest in withdrawing from Syria, prompting the Pentagon to draw up plans to do so.
There are also fears that ISIS could exploit the security situation in Syria after the fall of the Assad regime, since the new Syrian leadership and President Ahmad al-Sharaa have a limited number of forces with which to control all of Syria and also have to deal with allied foreign fighters from regions in Central Asia (although al-Sharaa downplayed that threat). However, continued U.S. strikes after the fall of the Assad regime targeting al Qaeda and ISIS in Syria demonstrates the continued threat. U.S. Central Command and the SDF continue to report successful joint missions against ISIS remnants.
The U.S. will need to balance its relationship between Baghdad and Erbil if it places more troops in the Kurdistan Region. The Iraqi Kurds would need security guarantees due to the larger U.S. deployment, including, potentially, missile defense systems with approval of Baghdad, to deter potential attacks on Erbil. If the U.S. withdraws from Syria, it should also hold talks with the Turkish government aimed at mitigating destabilizing military actions by Türkiye. The U.S. could support a renewed peace process currently under discussion in Türkiye between the Kurdistan Workers’ Party (PKK) and the Turkish state. There is also a need to seek new bilateral agreements between Baghdad and coalition countries if the coalition mission ends and to develop a special immigration visa program for Syrian and Iraqi partners in case the U.S. withdraws.
Current Military and Political Landscape
The Combined Joint Task Force–Operation Inherent Resolve (CJTF-OIR), established in October 2014, comprises troops from 25 countries and is part of the 87-member U.S.-led Global Coalition to Defeat ISIS. CJTF-OIR forces work with the Iraqi Counter-Terrorism Service, Joint Operations Command-Iraq, the Iraqi air force, the Iraqi and the Kurdish peshmerga, and associated anti-terrorism forces. Separately, there is also NATO Mission Iraq.
The U.S.-led coalition has around 2,500 troops in Iraq and maintains a military presence there across four key bases: Erbil Air Base in the Kurdistan Region, the Baghdad Diplomatic Support Center at the airport, the Union III base in Baghdad’s Green Zone, and Al Asad Air Base in Anbar province. In December 2021, the coalition announced it had transitioned from a combat to an advisory role in Iraq, after main operations against ISIS were ended in 2017. However, U.S. forces have continued to participate in partnered raids in Iraq, including one in western Iraq targeting ISIS in August 2024 in which seven U.S. troops were injured, and another on Jan. 6 in which one coalition member was killed.
Coalition advisers also work with the Ministry of Peshmerga Affairs (MoPA) to improve command and control, coordinate with Baghdad, and support MoPA reforms.
In Syria, approximately 2,000 U.S. soldiers are stationed throughout northeastern Syria’s Deir ez-Zor and Hasakah provinces including at Kharab al-Jir, the Rumailan Landing Zone, al-Shaddadi, Mission Support Site Green Village, Conoco, and the Al-Tanf garrison on the Syria-Jordan border, where they have backed operations by the Kurdish-led SDF since the battle of Kobani. Coalition forces also operate in Raqqah and have also monitored cease-fire efforts between Turkish-backed groups and the SDF in Manbij from the town of Kobani.
U.S. troops have remained partnered with the SDF since it defeated ISIS in March 2019 at the battle of Baghouz. The coalition also backs Syrian Free Army (SFA) at the Al-Tanf garrison near Syria’s border with Jordan and Iraq, which, after the fall of Assad, has expanded its influence to Palmyra.
Since the fall of the Assad regime, Syrian Kurds have faced attacks by Turkish-backed groups. Additionally, the new regime in Damascus has close ties to Türkiye and is discussing plans with Ankara to create Turkish bases in Syria.
The SDF in December was pushed by Turkish-backed groups from northern Aleppo and Manbij, and heavy fighting continues near the strategic Tishrin Dam. Türkiye conducted three cross-border operations since 2016 with the aim of reducing the SDF’s autonomy and has threatened to launch a new cross-border offensive. Türkiye views the SDF and the PKK – the latter of which has been designated a terrorist group by the U.S. – as equivalent. U.S. officials have underlined that their support for the SDF continues and have worked on preventing a new Turkish offensive.
Apart from assisting the SDF forces, the U.S.-led coalition also works to repatriate foreign nationals and assist the SDF in protecting prisons and camps holding ISIS families, such as al-Hol.
Relationship Dynamics Among the U.S., Iraqi Government, and KRG
Since Saddam Hussein’s fall in 2003, the Iraqi and Kurdish governments often have clashed over the budget, including peshmerga funding; oil exports; and disputed territories like oil-rich Kirkuk. Article 140 of the Iraqi Constitution mandates a referendum to decide whether these areas belong to the Kurdistan Region or Iraq, but it remains unimplemented.
After the U.S. liberation of Iraq, Kurdish peshmerga forces advanced to parts of Nineveh, Kirkuk, and Diyala despite opposition from Baghdad. In January 2010, U.S., Iraqi, and Kurdish peshmerga forces set up joint patrols in these areas to reduce tensions. In June 2014, the peshmerga moved into disputed territories after the Iraqi army fell apart amid an ISIS offensive. A month after the Kurdish independence referendum passed in September 2017, the Iraqi army pushed the peshmerga from the disputed areas. ISIS exploited the resulting power vacuum in the so-called Kurdistan Coordination Line dividing Iraqi armed forces, and the peshmerga in disputed territories. ISIS fighters have used these 3- to 5-kilometer (1.5- to 3-mile) security gaps to attack Iraqi and Kurdish security forces and have killed civilians as well as kidnapping and extorting them for money. As a result, the coalition pushed for the creation of joint Iraqi-peshmerga brigades to fill in the gap and sought more coordination between Baghdad and Erbil. Some Iraqi politicians had criticized the U.S. for providing artillery to Kurdish peshmerga, fearing this could empower those forces, which shows that future support has been carefully coordinated. In October 2017, there were also clashes between the peshmerga and Iraqi security forces after Iraq tried to advance on peshmerga positions. Iraq has recently used its power to reduce the Kurdistan Region’s autonomy.
Currently in the Kurdistan Region, Italy, France, Germany, the U.K., the Netherlands, and the United States play a mostly advisory role regarding peshmerga reform, as part of the Multi-national Advisory Group (MNAG) that supports the reform project to unite partisan units affiliated with rival political parties the Patriotic Union of Kurdistan (PUK) and the Kurdistan Democratic Party (KDP) under the MoPa.
Coalition participants have also provided training and weapons support to peshmerga and Iraqi forces during the anti-ISIS war. If U.S. forces were to leave, it would be difficult to maintain the reform program since it depends on technical and financial support from coalition and Western countries, and continued support would most likely be needed through new bilateral relationships.
Col. Walter van Bijlevelt, a former military adviser for the Dutch Consulate General in Erbil, underlined that the MNAG is not part of the coalition, so it could remain functioning as a separate entity. “OIR is a coalition and takes part of the MNAG as the seventh entity,” he told the authors of this report*.* DoD’s Counter-ISIS Train and Equip Fund (CTEF)-provided stipends to supplement salary payments to peshmerga personnel under the Ministry of Peshmerga Affairs. This will end in 2026. However, the coalition expects this support to continue beyond October 2026.
In December, the Dutch, Italian and German defense ministers visited Baghdad and Erbil to discuss the transition to bilateral security agreements and anti-ISIS fight amid the fall of the Syrian regime. Iraqi Foreign Minister Fuad Hussein told the report authors that Iraq is now discussing bilateral security relationships with the United States and other Western countries such as France. “It would be in a different form and shape,” Hussein said. “We already agreed that the NATO mission would stay.”
Dutch Defense Minister Ruben Brekelmans said discussions are ongoing about the coalition’s possible withdrawal and warned that whether or not it takes place, “If tensions in Syria increase, ISIS could strengthen its position there.” During his U.S. Senate confirmation hearing, Secretary of State Marco Rubio indicated there would be negative ramifications to the U.S. “abandoning partners who have a great sacrifice and threat, actually jailed the ISIS fighters.” and doubled-down in a March 9 statement, “The United States stands with Syria’s religious and ethnic minorities, including … the Kurdish community.” Iraq has reportedly also backtracked on a coalition withdrawal after the Syrian regime, which was an ally to the Iraqi government, fell. In February remarks at the Munich Security Forum, KRG President Nechirvan Barzani stressed that the timing is “not right” for the coalition to depart Iraq.
Factors Shaping Troop Repositioning
If U.S. troops remain in Iraq, they will face several security challenges. Although Baghdad has promised to protect U.S. coalition forces, Iranian-aligned armed groups have continued to attack those troops in Iraq and Syria using a mix of unmanned aircraft, surface-to-air missiles, and rockets. Iran-backed groups have launched at least 170 attacks on coalition forces since the Gaza conflict began on Oct. 7, 2023.
In addition, attacks on U.S. forces as part of a pressure campaign by Iran to force U.S. forces to leave Iraq predate the Gaza conflict. Apart from these, Iran and Iran-backed groups carried out 32 attacks in the Kurdistan Region between September 2018 and October 2023. The Ministry of Peshmerga Affairs’ Operating Concept identifies armed militias as one of the key threats. In January 2024, for instance, an Iranian ballistic missile attack killed Kurdish businessman Peshraw Dizayee.
The 2024 National Defense Authorization Act includes a provision for equipping peshmerga forces with air defenses to protect against such attacks. The Washington Post reported last year that the U.S. would expect to remain in Kurdistan after 2025 as a security guarantee against such attacks. Nevertheless, the presence of U.S. forces also makes the Kurdistan Region a target for Iran, especially if the U.S. forces are chiefly based in the Kurdistan Region. Increasing the U.S. troop presence in the Kurdistan Region could also create fears among Iraq’s neighbors that the U.S. would back an independent Kurdish state. Therefore, it would remain relevant to keep U.S. forces in Baghdad for coordination.
If U.S. forces and other countries’ militaries remain under bilateral agreements, stipends and support for peshmerga reform should continue to maintain a stable and capable force while countering Iran-backed militias, also because the MNAG is not officially part of the coalition.
Potential Steps for Repositioning and Their Implications
There already are troops from several coalition countries present at Erbil Air Base. Meanwhile, coalition forces evacuated Harir Air Base in the Kurdistan Region on Oct. 20, 2024. Iraq and the U.S. are planning to reduce the 2,500 troops in Iraq within two years.
Coalition forces continue to advise Iraqi and Kurdish security forces. Furthermore, special units are also involved in counterterrorism efforts. U.S., Italian, and French commandos are actively partnering with Iraqi and Kurdish anti-terrorism or peshmerga units to neutralize threats posed by ISIS cells. If the coalition departs Iraq, such operations would most likely come to halt, unless bilateral agreements are signed. But it’s highly likely these counterterrorism operations would continue limiting the risk of an ISIS resurgence.
Conclusion
To maintain trust with both Baghdad and Erbil in the face of the new U.S.-Iraq relationship, a balancing act that ensures no perception of favoritism toward the Kurdistan Region will be required. Therefore, a small contingent of U.S. forces should stay in Baghdad beyond any coalition drawdown to coordinate any operations with the Iraqi government.
ISIS conducted over 150 attacks in 2024 in Iraq and Syria, which is more than claimed by the group in 2023. Now after the fall of the regime and a fragile transitional Syrian government led by Hay’at Tahrir al-Sham and al-Sharra taking over Damascus, there is a risk ISIS could expand in central Syria. The U.S. and France conducted several airstrikes targeting ISIS in central Syria in December. U.S. officials have also been in contact with the new Syrian administration. Iraqi officials have also expressed fears that ISIS seized Syrian army weapons and are reorganizing its forces.
Moreover, concerns have surfaced in Western capitals that ISIS fighters and families being held in northeastern Syria could escape if Türkiye attacks the SDF. Therefore, further Western diplomacy is needed to contain this situation. Officials in Damascus have also shown interest in taking over control of the camps and prisons there.
Since U.S. troops in Syria rely on bases in Erbil, counterterrorism operations in Syria could continue, unless Trump decides to remove troops from Syria, risking a resurgence of ISIS. ISIS operations already have increased in Syria. Meanwhile, increased U.S. influence with the KRG could attract attacks by Iran-backed groups or the Popular Mobilization Forces, which would necessitate guarantees to protect Erbil.
A stronger presence in the Kurdistan Region would likely give the U.S. a greater influence on Kurdistan Regional Government’s Peshmerga reforms; however, the U.S. will likely continue stipend payments to the peshmerga in order to maintain a strong relationship with the KRG. Germany, the Netherlands, U.K., France, Italy, and other international military members of the anti-ISIS coalition will remain in Iraq and continue partnering and advising Iraqi security forces, especially the Kurdish peshmerga.
Though the number of U.S. troops in Iraq and Syria is relatively small compared to forward deployments abroad, such as 28,500 troops in South Korea, their presence plays a vital role in preventing the resurgence of ISIS and maintaining regional influence that would otherwise be filled by Iran, Russia, or even China.
Policy Recommendations
Reposition Troops: The Trump administration should maintain its current troop strength in Iraq. Repositioning some U.S. and coalition troops from Anbar to the Kurdistan Region will strengthen ties between units in Iraq and Syria while reducing the threat to U.S. troops who had previously been targets of Iran and its proxy militias.
Keep Troops in Syria: Remaining in northeastern Syria will ensure the victory against ISIS is preserved while also providing U.S. with leverage in the formation of the new Syrian government. U.S. and SDF personnel currently protect critical petroleum infrastructure that could benefit from U.S. investment to develop the oil and gas sector.
Peshmerga Reform: The United States should continue supporting peshmerga reforms, conditional upon progress in achieving the reform goals as well as the KDP and PUK forming a new government.
Permanent Basing of Troops: The Defense Department should consider options for permanent basing of troops in Iraq’s Kurdistan Region and increased funding for military construction of barracks, headquarters, and a detention facility in northeastern Syria.
Energy Independence and Banking Reform: The Trump administration should continue to support Iraq’s economic growth and energy independence by eliminating waivers for Iran to sell Iraq electricity, prodding Baghdad to restore oil exports through the Iraq-Türkiye pipeline, and guiding Iraq’s banks through reform to provide more confidence to Iraqi and foreign investors.
Security Guarantees: The Iraqi Kurds also will need security guarantees due to the larger U.S. deployment, including potential deployment of missile defense systems, to prevent potential attacks. This should be done transparently and with Baghdad’s consent to avoid further tensions through joint security agreements. Iran should also be warned not to carry out attacks on Iraqi Kurds either through proxies or with ballistic missiles from Iran.
Regional Cooperation: Involving Türkiye in discussions around U.S. military activities in Iraq and Syria could help mitigate destabilizing Turkish military actions. The U.S. could support a renewed peace process currently under discussion in Türkiye between the PKK and Ankara. Furthermore, the U.S. can continue to support the SDF while it integrates into the Syrian Ministry of Defense.
Bilateral Agreements: Iraq needs to quickly develop bilateral agreements with coalition countries besides the U.S., considering both the uncertainty of what will happen after 2026 and current developments in Syria.
Visa Program: If the U.S. does withdraw from Iraq and Syria, it should create a special immigration visa program for Syrian partners and ensure continuity for Iraqi partners to protect those who risked their lives to partner with the U.S.