Post-Alliance: The Power Vacuum and Challenges of Counterterrorism Efforts in Iraq and Syria

Prepared by: Fedaa Mansour

Researcher in the Security and Terrorism Program

Since 2014, the military presence of the international coalition in both Iraq and Syria has served as a cornerstone in limiting the expansion of extremist organizations in general and the Islamic State (ISIS) in particular, by providing direct support through intelligence and logistical assistance to local forces (Iraqi security forces and Syrian opposition groups). In parallel, the United States has viewed this support as part of its broader Middle East strategy, wherein the stability and strength of local Iraqi and Syrian forces contribute to safeguarding U.S. interests, curbing the spread of Iranian influence and terrorist groups in the region, and preventing the Iraqi army from becoming a parallel force aligned with Iran-backed factions. In this context, the security landscape in both countries has begun to witness fundamental shifts following announcements of gradual withdrawal or repositioning plans by the United States and the international coalition. These developments are reviving scenes of chaos and the resurgence of extremist cells. Accordingly, the withdrawal raises profound questions regarding the future of counterterrorism efforts against ISIS, particularly in light of fragile local security infrastructures, ongoing political divisions, and the multiplicity of regional and international actors competing for influence. Does this withdrawal create a security vacuum that will lead to the reemergence of terrorist threats? Or could it open the door to new arrangements that recalibrate the equation of security and stability?

Starting from these pressing questions, this article seeks to analyze the impact of the U.S.-led international withdrawal on counterterrorism efforts especially against ISIS in Iraq and Syria. It does so by deconstructing the security and military contexts, tracking field-level changes, and projecting future implications based on current realities, bearing in mind that the withdrawal represents a significant shift in Washington’s military and security posture in the region.

Firstly: The Security and Strategic Context before the Withdrawal

An international coalition to combat terrorism and eliminate the Islamic State (ISIS) in Iraq and Syria was announced in September 2014, during the presidency of Barack Obama. The coalition, led by the United States, launched joint military operations targeting ISIS fighters in both countries. American forces constituted the core of the international coalition, which initiated its operations with airstrikes aimed at ISIS positions. Accordingly, the coalition’s presence represented a crucial security guarantee, effectively curbing the expansion of terrorist organizations through aerial and intelligence support that enhanced the operational capabilities of local forces in Iraq and Syria. This dynamic can be understood through the following: –

– The Security Situation in Iraq and Syria before the Withdrawal

1. Relative Stability in Some Areas and Security Fragility in Others: It is worth noting that the international coalition provided support to local armed groups in both Syria and Iraq to enable them to carry out the mission of defeating ISIS. Initially, military operations were launched, followed by security and intelligence efforts. These missions inherently required capable local forces to maneuver and establish control in areas liberated from ISIS. At its peak, ISIS controlled nearly one-third of the territory in Iraq and Syria Before its defeat, first in Iraq by the end of 2017, and later in Syria in 2019.[1]

In Iraq, coalition forces supported Iraqi security forces through a range of programs that significantly contributed to enhancing their capacity to confront terrorist threats and reestablish control across most territories. This support largely falls under the security agreement signed between Baghdad and Washington in 2009. Between 2015 and 2023, the United States provided approximately $13.8 billion[2] in funding to Iraq. Beyond financial assistance, the U.S. developed comprehensive training programs for over 20,000 Iraqi soldiers and security personnel in various security and military fields, such as counterterrorism tactics, intelligence techniques, surveillance, and reconnaissance. These troops were trained within U.S. bases in Iraq. Despite these efforts, ISIS cells continue to operate in remote areas and regions adjacent to major cities, such as Baghdad’s outer belt, and the outskirts of Diyala and Anbar provinces, as well as the Hamrin Mountains in the country’s east.

In Syria, coalition support was directed primarily toward the Syrian Democratic Forces (SDF) in northeastern Syria, including areas such as Hasakah, Deir Ez-Zor, Raqqa, and al-Tanf regions where ISIS has recently begun to resurge. The SDF, established in 2015, became the coalition’s primary local partner in executing counterterrorism operations in Syria. It also played a key role in protecting vital oil fields to prevent ISIS from regaining control over them. Throughout their 8-year relationship, the SDF received consistent financial assistance from coalition members. This included the provision of salaries for fighters and administrative personnel, ranging from $100 to $800 per month[3], making it one of the highest-paid local armed groups in the region.

2- Decline in ISIS Activity Without Its Total Elimination: All forms of support provided by the international coalition forces have significantly contributed to weakening ISIS. A U.S. intelligence report revealed a sharp decline in ISIS attacks in Syria during the third quarter of 2021. According to the report, ISIS attacks in Syria decreased by 86%[4], with the number of attacks dropping from 132 in July, August, and September of 2020 to just 19 during the same months in 2021.

Secondly: The implications of the U.S. and International Coalition Withdrawal

– The Nature of the Withdrawal

In Iraq, the idea of withdrawing international coalition forces was not new when it was announced under President Joe Biden in January 2024. The plan involved a phased withdrawal to be completed by September 2025, just one month before Iraq’s upcoming parliamentary elections. Under the new arrangement, the presence of coalition forces would be limited to an advisory-only role. However, the withdrawal traces back to the 2008 Strategic Framework Agreement, which committed the U.S. administration to withdraw from Iraq by a specific deadline. Part of the forces indeed left in 2011, followed by a 2020 parliamentary vote calling for the expulsion of foreign troops yet the full withdrawal did not occur on schedule, and some forces remained until December 2021. Since then, the number of U.S. troops has been reduced to 2,500, although negotiations resumed in light of the ongoing Israeli war on Gaza. The United States has continuously sought to end what President Biden refers to as the “endless wars” in the Middle East.

In Syria, the situation developed differently. On March 10, the new Syrian administration, led by Ahmad al-Sharaa, signed an agreement in Damascus with Mazloum Abdi, the commander of the Syrian Democratic Forces (SDF). Following the agreement, the U.S. Department of Defense (Pentagon) announced its intention to reduce the number of American troops in Syria to fewer than 1,000 over the coming months, aiming for completion by September 2026. According to The New York Times, the U.S. military has already begun reducing its troop presence in Deir Ez-Zor and Raqqa, and is preparing to shut down 3 out of its 8 military[5] bases in the region. This process is considered a repositioning rather than a complete withdrawal.

– Declared and Undeclared Reasons for the Withdrawal and Repositioning

Iraqi Prime Minister Mohammed Shia’ Al-Sudani stated that, despite his appreciation for U.S. assistance, American forces have become a source of instability, as they are frequently targeted and often respond with retaliatory strikes without coordination with the Iraqi government. Several factors have thus contributed to the reduction of international coalition forces: –

1. Shifting U.S. Priorities: While the coalition initially focused on combating the Islamic State (ISIS), U.S. officials acknowledge that their presence in Iraq and Syria also offers a strategic vantage point to counter Iranian influence. This positioning has gained increasing importance amid the escalating regional confrontation between Israel and Iran. In recent months, U.S. forces in Iraq have participated in intercepting missiles and drones launched toward Israel, while also responding to an upsurge in near-daily exchanges of attacks between Iran-aligned armed factions and U.S. forces stationed in Iraq and Syria. Since the outbreak of the war between Israel and Hamas on October 7, U.S. troops have come under attack more than 165 times.

While Washington justified its actions as part of its right to self-defense, the Iraqi government viewed such strikes as hostile acts that undermined Iraq’s national interests, sovereignty, and stability, and exceeded the agreed-upon scope of the coalition’s mission against ISIS.

2. Domestic Pressures: Internal tensions have grown significantly since the U.S. airstrike in early 2020 that killed Qassem Soleimani, commander of Iran’s Quds Force, and Abu Mahdi al-Muhandis, deputy head of Iraq’s Popular Mobilization Forces (PMF). That incident led the Iraqi government to perceive the continued presence of U.S. forces as a threat to national sovereignty. Additionally, there has been mounting pressure from pro-Iran political factions, which argue that the U.S. military presence reflects a broader American strategy to expand its influence in the region. On a broader level, the withdrawal plans signal a wider U.S. retrenchment from Middle Eastern conflicts, shifting the burden of regional stability onto regional actors, particularly Turkey, which is repositioning its priorities to confront China’s growing rise a development perceived as a threat to the stability of the international order. This shift is occurring amid rising tensions in the South China Sea and an ongoing U.S. China economic confrontation, especially following former President Trump’s imposition of tariffs on Chinese goods.

Thirdly: Security Implications

– Implications for Iraq

1- Potential Sunni-Kurdish Tensions: The withdrawal of foreign forces from Iraq may reignite sectarian tensions between Sunni and Kurdish communities, particularly due to the legacy of past sectarian conflicts that altered the demographic composition of several areas in Baghdad and other mixed provinces, despite the presence of U.S. forces.

2- Risk of Economic Collapse:[6] Iraq faces the possibility of a severe economic downturn, potentially marked by a sharp increase in the dollar exchange rate and the government’s inability to meet its financial obligations related to public projects and operational expenditures.

3- Political Leverage for the Iraqi Government: The removal of coalition forces aligns with the Iraqi government’s political agenda, and thus may be framed as a political achievement, reinforcing its domestic legitimacy.

4- Weakening of Security and Intelligence Capabilities: The lack of training, technological support, and coordination mechanisms post-withdrawal is expected to undermine the operational performance of Iraqi forces in their independent fight against ISIS.

5- Empowerment of Armed Factions as an Unregulated Alternative: The vacuum left by the coalition could enable militias to emerge as alternative power brokers, potentially redirecting counterterrorism efforts toward sectarian and political agendas rather than national security objectives.

– Implications for Syria

1. The withdrawal of coalition forces, especially U.S. troops from certain bases in northeastern Syria may undermine the security environment that had previously ensured a relative degree of stability in areas under the Autonomous Administration. The Syrian Democratic Forces (SDF) are now facing dual pressure: on one front, from the resurgence of ISIS cells in the desert (al-Badiyah), and on the other, from ongoing Turkish threats to launch cross-border military operations. With the reduction in U.S. aerial and intelligence support, the SDF has become strategically exposed.

2. The situation is further complicated by the involvement of regional actors and the clash of conflicting agendas, which has led to a distortion of the direction of confrontation. Recently, Turkey has prioritized targeting the SDF over fighting ISIS. Thus, its claim of combating terrorism refers to “Kurdish terrorism” rather than “jihadist terrorism.”

– Shared Implications

1- The withdrawal is likely to shift the current regional balance of power in favor of Iran,[7] due to its possession of loyal Shiite militias, which it seeks to use to fill the resulting vacuum, strengthen its regional influence, and replicate the Hezbollah model in Iraq. In addition, Turkey is engaged in military operations against the active Turkish Kurdistan Workers’ Party (PKK) presence in northern Iraq. Accordingly, the withdrawal would benefit both countries.

2- A decline in intelligence capabilities: the reduction of international military presence leads to diminished capacity for conducting precise operations against the Islamic State (ISIS), particularly in border regions.

3- The resurgence of ISIS, taking advantage of the security vacuum left by the withdrawal. Although the group currently exists in small remnants, it may regain strength and momentum due to weakened monitoring and pursuit capabilities in the absence of U.S. air support. This could lead to a rise in sophisticated attacks, especially in areas such as Diyala and Kirkuk. On the other hand, ISIS has begun to mobilize in the Syrian desert (al-Badiyah) and eastern countryside, expanding its operations recently by exploiting the preoccupation of other powers. Despite calls for coalition forces to withdraw, Iraq, during its meeting with the international coalition last April, emphasized the need to maintain security in Syria.

4- The U.S. withdrawal may be perceived as a troubling signal by some allied countries, such as Saudi Arabia and other Gulf states, as well as Israel. The recent developments in Saudi-Iranian relations, under Chinese sponsorship, may reflect a trend toward diversifying partners and expanding diplomatic margins beyond traditional frameworks.

In conclusion, it becomes clear that the withdrawal of the international coalition forces from Syria and Iraq does not signify the end of the terrorist threat; rather, it may mark the beginning of more complex transformations. The power vacuum left by the withdrawal has not been filled by stability or local agreements, but instead by a race for influence and security maneuvering. Moreover, a complete withdrawal of coalition forces from the region is unlikely shortly, with strong indications to support this view, especially considering that the current regional context does not permit such a withdrawal. The coalition’s primary objective remains to secure Israel’s eastern front on one hand and continue the military and political containment of Iran on the other. This is particularly critical given Iran’s potential to fill the resulting political and military void, especially as it has shown recent signs of convergence with ISIS. Additionally, the withdrawal would provide a significant opportunity for both Russia and Turkey to shape the post-U.S. security and political arrangements in Iraq and Syria. Therefore, the coming stage calls for a reassessment of counterterrorism strategies, one that is built on effective regional coordination, away from conflicting interests and external interventions.

References

[1]– “Post-Daesh: France’s engagement”, France diplomacy. Look at

[2]– Muhannad Faris, “US Support for Iraqi Security Forces: Challenges and Future Prospects Under Trump”, Washington institute, March 2025. Look at

[3]– أنس شواخ، “العلاقة بين التحالف الدولي وقوات سوريا الديمقراطية: الواقع والمستقبل”، مركز جسور للدراسات، أكتوبر 2023، ص 7.

[4]-” التحالف الدولي في سوريا والعراق .. المهام والأهداف”، المركز الأوروبي لدراسات مكافحة الإرهاب والإستخبارات، فبراير 2022. على الرابط الآتي

[5]– إبراهيم حميدي، ” المطالب الأميركية الثمانية من سوريا .. ماهي، وكيف ردت دمشق عليها؟”، مجلة المجلة، إبريل 2025. على الرابط الآتي

[6]– مصطفى السراي، “قوات التحالف الدولي في العراق: قراءة في قلق الخروج”، مركز البيان للدراسات والتخطيط، 2024، ص 5 – 6.

[7]– فراس عبد الكريم، “تداعيات إنسحاب قوات التحالف الدولية على العملية السياسية في العراق”، مركز حمورابي للبحوث والدراسات الإستراتيجية، إبريل 2024، ص 7.