The Trump Administration Is on the Clock to Decide Whether Operation Inherent Resolve Should End

Will President Donald Trump override his predecessor’s decision to shut down Operation Inherent Resolve in Iraq by September 2025? While it has yet to clarify its vision of future U.S. military involvement in Iraq, the Trump administration is faced with a choice: continue with the current plan, extend the mission under new terms, or move up the end date of the mission in line with a stated preference of a complete U.S. troop withdrawal. Among these three options, the looming threat of an Islamic State resurgence makes an accelerated drawdown of Operation Inherent Resolve highly inauspicious. The transition of complete operational responsibility to the Iraqi Security Forces carries a great deal of risk. While currently capable of containing the Islamic State, the sudden absence of crucial U.S. military and intelligence support could render the Iraqi Security Forces unable to maintain the upper hand, leaving Iraq’s relatively stable but fragile security situation vulnerable to exploitation once more — a potential disaster only exacerbated by the current and future uncertainty in Syria following the recent downfall of the Assad regime.

As Operation Inherent Resolve approaches its expiration date, the Trump administration is on the clock to identify a future security arrangement for Iraq to mitigate the risk of an Islamic State resurgence. Relocating troops to a smaller operation in Erbil in the Iraqi Kurdistan region is a viable option that could significantly lower operational costs and reduce U.S. forces’ exposure to attacks from Iranian-backed militias. Such a solution will, by and large, enable the United States to still balance Iran’s quest for regional hegemony while keeping response capabilities to a potential Islamic State resurgence close.

The Rise of the Islamic State and Operation Inherent Resolve

 In 2014, the Islamic State of Iraq and the Levant made rapid territorial gains, conquering the city of Raqqa in Syria and even the second-largest city in Iraq, Mosul. Just days after the fall of Mosul, the United States initiated military strikes to halt the terrorist group that had, in record time, gained worldwide notoriety for its widespread atrocities. The strikes did not stop the Islamic State of Iraq and the Levant from declaring the creation of a transnational caliphate and rebranding itself as the Islamic State, unbound by the internationally recognized borders of Iraq and Syria. In response, the U.S. Department of Defense established an international coalition called the “Combined Joint Task Force – Operation Inherent Resolve” in October 2014 to “defeat” the Islamic State in “designated areas” of the two countries and to set “conditions for follow-on operations” to promote regional stability.

By 2017, the U.S.-led coalition and Iraqi government forces declared the territorial defeat of Islamic State in Iraq, as the group no longer controlled large swaths of territory in the country. In December 2021, Operation Inherent Resolve shifted to a non-combat mission, providing training, advice, and intelligence support to Iraqi forces. At present, the U.S.-led coalition includes approximately 2,500 American troops in Iraq and another 900 in Syria.

Debates over ending Operation Inherent Resolve have persisted since 2021. However, the deliberations intensified in 2024. In late September, the United States and Iraq agreed to end the U.S.-led mission by September 2025 and to withdraw U.S. troops from the country, but it was unclear how many would leave and from which bases. While 900 U.S. troops are signaled to remain in Syria until the end of 2026, the number staying in Iraq remains uncertain, though some might stay. The agreement does not entirely end U.S. military involvement in Iraq but likely transitions the cooperation to a bilateral security partnership, prioritizing intelligence sharing and counter-terrorism operations with special forces. This new partnership could be led by the U. S. Special Operations Command and based in the city of Erbil in the semiautonomous Iraqi Kurdistan region, which historically has close ties with the U.S. government. The impending transition is expected to reduce operational costs and lessen force protection concerns but may complicate cooperation with the Iraqi Security Forces due to the increased distance from Baghdad. The extent to which Kurdish regional security forces, such as the Peshmerga special forces, will be involved in this transition remains uncertain and will likely depend on the level of threat posed by the Islamic State. From the Iraqi government’s perspective, a new security arrangement based on support through bilateral agreements offers greater opportunity to engage with partners other than the United States. The flexibility to engage bilaterally with European powers, such as Germany and France, as well as regional partners, such as Saudi Arabia and Turkey, will provide Iraqi Prime Minister Mohammed Shia al Sudani’s government with options that can sidestep the anti-Americanism of Iranian-backed power brokers and groups such as the Popular Mobilization Forces — an Iraqi state-sponsored paramilitary network of approximately 67 factions heavily influenced by Iran. For the United States and NATO, the challenge lies in whether the bilateral transition can adequately replace the capabilities provided by Operation Inherent Resolve’s framework, as Iraq’s stability likely remains a shared interest.

A Farewell to U.S. Forces in Iraq?

Unsurprisingly, Iran and the Popular Mobilization Forces are thrilled about the prospect of an Iraq without Operation Inherent Resolve: This is not new. Yet, what changed in 2024 was Baghdad and Washington’s willingness to raise doubts about a future U.S. military presence in Iraq. When Sudani visited Washington in April 2024, the withdrawal of coalition forces from his country was at the top of his agenda.

Under the Biden administration, Washington’s interests were diminishing as well. The presence of U.S. troops in the Middle East had become increasingly dangerous as tensions steadily grew following Hamas’ Oct. 7th attack on Israel and the subsequent war in Gaza. The side effects of the regional conflicts hit Iraq relatively hard between October 2023 and February 2024 as Iran-aligned militias in Iraq conducted almost 200 strikes on U.S. and coalition troops in Iraq and Syria. The attacks temporarily paused only after three U.S. soldiers were killed in an outpost in Jordan in late January 2024, prompting the United States to retaliate. The response included a drone strike in Baghdad, which killed a commander from Kataib Hizballah, a paramilitary group in the Popular Mobilization Forces. Throughout the summer, the frequency of attempted strikes on U.S. forces continued, but these strikes have since stopped completely. With Israel breaking the ceasefire in Gaza, it is too soon to tell whether these strikes will resume. Recently, the Iraqi government has shown hesitation with regard to ending the U.S. military presence, fearing potential fallout from Syria after Assad’s fall. However, the decision now largely rests with the new Trump administration.

 Trump Back in the White House

With Donald Trump as president again, a shift in U.S. policy in the Middle East is expected. However, despite two months in office, it is still unclear how the change will unfold. A strongly pro-Israel Trump administration could opt to keep U.S. troops in Iraq either by extending Operation Inherent Resolve’s current mission as it is or by extending its mission under new terms. Under new terms, the primary goal would be to maintain an American presence in support of Israel’s regional security issues, and containing the Islamic State would only be a secondary priority. U.S. National Security Advisor Mike Waltz and Secretary of State Marco Rubio are both known for their strong support for Israel and for their hawkish stance on Iran, suggesting the United Staes would give Israel free rein to address its national security interests. Shortly after taking office, the Trump administration suspended the entire U.S. Agency for International Development program, except for military aid to Israel and Egypt. As a result, the administration has now approved nearly $12 billion in military sales to Israel since Trump took office, with Rubio signing a declaration on March 2nd to expedite $4 billion in additional aid. In January, Waltz stated that the United States would support Israel in “doing what it has to do” if Hamas violated the ceasefire — underlining a future unconstrained Israeli position. Following Trump’s Feb. 5th proposal to take over Gaza during Israeli Prime Minister Benjamin Netanyahu’s visit to Washington, Waltz reaffirmed the American-Israeli shared goal that “Hamas cannot stay there.” While the Trump administration appears committed to strong material and rhetorical support for Israel, this doesn’t necessarily mean maintaining a U.S. military presence in Iraq. As a withdrawal could increase the threat to Israel from Iranian-backed militias in Iraq, this could prompt Netanyahu to push for a continued U.S. presence. However, with Iran weakened by Hizballah’s defeat in Lebanon, the fall of the Assad regime and the diminished role of Hamas in Gaza, the immediate regional threats to Israel have been weakened significantly, thus decreasing the incentive for the Trump administration to keep U.S. troops in Iraq and Syria as a security backstop for Israel.

Alternatively — and perhaps a more likely scenario than seeking to extend Operation Inherent Resolve — the Trump administration could choose to do nothing and let the Biden administration’s plan unfold. So far, neither President Trump nor his administration has made any public statements on the future of the U.S. military presence in Iraq. Given the torrent of domestic and foreign policy moves already in the first two months of his presidency, it is possible that this issue is not on his radar yet.

However, since Biden’s plan does not fully end U.S. involvement in Iraq, a third option appears most likely: opting for an accelerated drawdown either by advancing the mission’s end date or overriding the transition to a new bilateral security arrangement. In 2020, the first Trump administration repeatedly expressed its intention to withdraw all U.S. troops from Iraq, emphasizing that this had been a key objective since Trump first took office. Meanwhile, the inclusion of both Rubio and Waltz in Trump’s national security inner circle suggests that the second Trump administration will at long last prioritize China in U.S. foreign policy. Meanwhile, in a post-Assad Syria, Turkey has repeatedly called for its allies to withdraw support for the Kurds, aiming to expel the U.S.-backed Syrian Democratic Forces from northeast Syria, which currently plays a decisive role in containing Islamic State in the area. If Trump chooses to deprioritize the Middle East, he could opt to leave Israel and Turkey to manage the security situation in Syria. This would not eliminate the potential for spillover violence in Iraq. For these reasons, strong U.S. support for Israel could signal that Trump wants to enable the regional powers to fill the impending security vacuum in the Middle East themselves, thus choosing an accelerated drawdown of Operation Inherent Resolve. If this scenario plays out, it increases the likelihood of a disorderly withdrawal that would leave Iraq more vulnerable as the transition of operational responsibility to the Iraqi Security Forces would be hastier — driven by a fixed timeline rather than their readiness to tackle the security challenges.

At present, Operation Inherent Resolve’s fate might be tied more to Israel’s security concerns and U.S. foreign policy priorities than to the original goals of containing the Islamic State while bolstering the capability of the Iraqi Security Forces. Both objectives factor greatly into Iraq’s future stability.

Containing the Islamic State

The Islamic State is certainly not the terror powerhouse it was a decade ago, but key observers still warn of a potential resurgence if the United States withdraws from Iraq and Syria. Steven Heydemann, a nonresident senior fellow at the Brookings Institution, argues that Operation Inherent Resolve’s mission can, in no manner, be declared accomplished. He refers to a United Nations report from 2023, which states that the Islamic State still has between 5,000 and 7,000 fighters in Iraq and Syria. There are even some signs pointing to the Islamic State increasing its level of activity, especially in Syria with reports of attacks tripling in 2024 compared to 2023 and increasing activity since Assad’s downfall. Furthermore, the Wall Street Journal reports on the Islamic State mustering forces in Syria’s Badiya desert, where it trains suicide bombers and directs small but potential deadly attacks on Operation Inherent Resolve forces. The absence of a U.S.-led troop presence could create the same security vacuum that the Islamic State exploited a decade ago, with the risk of resurgence in Syria eventually spilling over to Iraq as previously seen.

With Operation Inherent Resolve present, a large portion of Islamic State supporters function as so-called “sleeper cells” that lie dormant until they receive orders or decide to act independently. The concerning situation in al-Hol and al-Roj camps in northeast Syria — which house families and former members of the extremist organization alongside its larger refugee population — is difficult not to view as a ticking bomb and an incubator for the next generation of jihadists. The organization has a strong informal presence there and, with a high level of success, indoctrinates children according to its extremist principles. Currently, the Syrian Democratic Forces is responsible for the security of the camps, which has grown increasingly challenging in Syria’s fragile security situation. If Turkey and Turkish-backed groups in Syria, such as the Syrian National Army, escalate their fight against the Syrian Democratic Forces, it could compromise security around the al-Hol and al-Roj camps. Additionally, if the Trump administration chooses to accelerate the drawdown of Operation Inherent Resolve and completely withdraw U.S. support for the Syrian Democratic Forces, Turkey would have the freedom to intensify its military actions against the Kurdish forces in northeast Syria without fear of damaging its relationship with the United States. Though the new Syrian leadership and the Syrian Democratic Forces have recently reached an agreement and the Kurdistan Workers’ Party has issued a statement that it will lay down its arms, it is very unlikely that this progress will be a sufficient replacement for U.S. political, military, and economic engagement. Recent unrest in Syria between fighters from Hayat Tahrir al Sham and supporters of the former regime also raises the question of whether the new Syrian leadership will be able to establish a sound violence monopoly. Combined, these factors could undermine efforts to contain the Islamic State, making U.S. disengagement strategically risky, since this vacuum could very well ignite the looming threat of Islamic State resurgence.

If the situation in Syria spirals out of control, the key question remains: Can the Iraqi Security Forces manage the likely growing threat of the Islamic State if U.S. support decreases?

Averting an Islamic State Resurgence in Iraq

Some observers assess that the Iraqi Security Forces have improved their ability to conduct counter-terrorism operations. However, the future challenge for the Iraqi Security Forces is not their immediate readiness to contain the Islamic State but rather their ability to maintain this level of capacity without U.S. intelligence support and the NATO military presence’s stabilizing effect through deterrence. The Iraqi Security Forces are currently combating the Islamic State on a one-dimensional security level, applying kinetic force to fight and defeat Islamic State jihadists, but Baghdad has not made any significant progress in combating the underlying grievances for mobilization to the caliphate. Therefore, the Islamic State still exerts a significant level of ideological and theological influence on the Sunni-marginalized rural environments with high levels of unemployment, backwardness, and poverty as well as a lack of health and educational services — making a risk of resurgence plausible.

The Iraqi government’s inability to address the underlying structures sustaining Islamic State development mirrors its failure to tackle the issues that will eventually undermine any progress within the Iraqi Security Forces. Like the rest of Iraq, the Iraqi Security Forces are challenged by weak institutions, pervasive corruption, and a lack of reforms. A major challenge that will remain in the wake of a decision to close Operation Inherent Resolve will be transitioning operational responsibility to the Iraqi Security Forces, which will likely require a transition of authority of at least six months, making an accelerated drawdown riskier.

In addition, the Popular Mobilization Forces, with approximately 200,000 fighters, both bolster and complicate the efforts of the Iraqi Security Forces in containing the Islamic State. While the Iranian-backed militias were pivotal in defeating the Islamic State territorially in 2017, their de facto autonomy highlights the Iraqi government’s lack of control over the national monopoly on violence. This dynamic creates uncertainty within Iraq’s security system, increasing the risk of internal conflicts and complicating a unified response to any Islamic State resurgence. Officially, there is strong cooperation between the Iraqi government and the Iraqi Security Forces on one side and the Popular Mobilization Forces on the other. However, through the Royal Danish Defence College’s joint capacity-building activities with the Iraqi Defense University for Military Studies, we have often heard private accounts of tensions and conflicting interests between the two. Iran-influenced factions within the Popular Mobilization Forces have secured influential political positions and, with more fighters than the Iraqi Security Forces, can exert significant influence over security-related decisions and actions. This imbalance will only increase as U.S. operational and intelligence support for the Iraqi Security Forces diminishes, allowing Iran to exert even greater influence over Iraq’s security.

As Operation Inherent Resolve potentially enters its final phase, the Trump administration has yet to decide on its exact approach. With three possible options on the table, the most likely choice appears to be an accelerated drawdown, prioritizing a shift in dominating Middle East security from the United States to regional players like Israel, Turkey, Saudi Arabia, Iran, and, to some extent, Iraq — each with differing priorities. However, with Iraq being the weakest country among them, a sudden decrease of U.S. military support could very well leave its security forces overwhelmed if the looming catastrophe of an Islamic State resurgence ignites.

Anders Streubel-Kristensen is head of section at the Centre for Stabilisation at the Royal Danish Defence College’s Institute for Strategy and War Studies. He is specifically employed as part of the center’s contribution to the Danish Peace and Stabilisation Fund’s Iraq program. His research focuses on security politics in Iraq.

David Vestenskov is a senior adviser and director for the Section for Cooperative Security works at the Royal Danish Defence College. His research focus for the past ten years has been on international security policies in Afghanistan, Iraq, and the Middle East. From 2022 to 2023, he was posted in Bagdad, Iraq, as an advisor for NATO’s Defence Education Enhancement Programme within NATO Mission Iraq.

The opinions in the piece are the author’s alone and do not reflect the official policy of any Danish government entity.

Image: Lance Corporal Zachery Laning, U.S. Marine Corps

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