US withdrawal reshapes Iraq’s security order, exposing Kurdistan to new risks while testing Baghdad’s sovereignty and defence capacity.

Dr. Pshtiwan Faraj

The United States is preparing to complete the withdrawal of its remaining military forces from Iraq by September 30, closing a 23-year chapter that began with the 2003 invasion and evolved into a long-term counterterrorism partnership. For Baghdad, the departure represents the restoration of sovereignty and the transition toward a bilateral security relationship. For Erbil, however, the same event is being experienced through a fundamentally different security lens. The immediate question is not whether Iraq should possess greater sovereignty, but what happens to the security architecture that has protected the Kurdistan Region while that sovereignty remains contested in practice. The withdrawal therefore exposes a strategic contradiction at the centre of post-ISIS Iraq: Baghdad is gaining greater formal control over national security, while the Kurdistan Region is losing an external layer of protection before it has acquired the capabilities required to replace it.

The timing makes the transition particularly consequential. The United States and Iraq agreed in 2024 to wind down the coalition's military mission in Iraq and move toward a bilateral security relationship. The coalition's presence in most federal Iraqi territory was already substantially reduced, while the remaining forces in the Kurdistan Region became the final component of the withdrawal process. Iraqi officials have repeatedly described September 30 as a fixed and final deadline and have presented October 1 as the beginning of a new phase of Iraqi sovereignty. Yet the strategic environment in which that transition is occurring is radically different from the environment in which the withdrawal timetable was negotiated. The question is no longer simply whether ISIS requires an international military coalition. It is whether Iraq can manage the competing pressures of Iran, armed groups, Kurdish security concerns, regional escalation and transnational jihadist networks without the stabilising presence of American forces.

For the Kurdistan Region, the most immediate problem is air defence. Kurdish Prime Minister Masrour Barzani has argued that the region is vulnerable to Iranian missiles and drones and that the Kurdistan Regional Government does not possess an independent aerial defence system capable of dealing with sophisticated attacks. The KRG says that more than 1,000 Iranian drones and missiles have targeted Iraqi Kurdistan since the outbreak of the current US-Iran conflict in February, although the precise attribution and accounting of individual attacks remain matters of political and security reporting. American defensive systems around Erbil have intercepted some incoming threats, while the removal of those systems will eliminate a capability that the KRG cannot easily reproduce on its own.

This creates an important distinction between military withdrawal and the withdrawal of deterrence. American troops are not merely another armed formation leaving Iraqi territory. Their presence has represented an implicit warning that attacks on US personnel, facilities or partners could trigger an American response. Once that presence disappears, the calculation of potential attackers changes. Iran and Iran-aligned armed groups will have to reassess the risks associated with targeting the Kurdistan Region, while Erbil will have to calculate whether its existing political relationships and security capabilities are sufficient to discourage attacks. The absence of American forces therefore changes the strategic equation even if no immediate attack occurs.

The issue is particularly sensitive because the Kurdistan Region occupies a peculiar position within the Iraqi state. It possesses constitutionally recognised autonomy and its own security forces, but it does not exercise the same sovereign authority over defence procurement and external security that an independent state would possess. Barzani has argued that the KRG cannot independently acquire the sophisticated air-defence systems it requires because major military purchases must pass through Baghdad. This produces a paradox: Erbil is expected to defend itself against external threats but remains dependent on federal institutions for some of the capabilities necessary to do so.

That paradox turns the American withdrawal into a Baghdad-Erbil question as much as a Washington-Erbil question. If Baghdad wants the withdrawal to demonstrate that Iraq has become capable of defending its territory independently, then the federal government faces a corresponding responsibility to ensure that the Kurdistan Region is incorporated into that national defence architecture. Otherwise, the withdrawal could deepen rather than resolve the security imbalance between the federal government and the autonomous region. The issue is therefore not simply whether the KRG should have its own air force or missile defence system. It is whether Iraq can develop a genuinely national security system in which Kurdish territory is protected as part of Iraq's sovereign defence structure.

This is where the unresolved question of Iraqi armed groups becomes strategically important. The Iraqi government has sought to link the transition toward full sovereignty with the principle that weapons should ultimately be under state authority. Prime Minister Ali al-Zaidi told the United Nations General Assembly that Iraq's objective is for the state to be the sole authority making decisions of war and peace and for weapons to remain in the hands of constitutional institutions. He also presented the end of the coalition mission as a transition from military cooperation toward economic cooperation with international partners.

The difficulty is implementation. The American withdrawal removes a foreign military presence, but it does not automatically resolve the problem of non-state armed power inside Iraq. Reporting in September indicated that the withdrawal and militia disarmament deadlines were occurring simultaneously, while several powerful Iran-aligned armed groups showed little indication that they intended to surrender their weapons. This creates a structural contradiction in the post-withdrawal order. The Iraqi state is becoming more formally sovereign at precisely the moment when its monopoly over organised force remains incomplete.

For Erbil, that distinction matters enormously. The Kurdistan Region has spent decades attempting to preserve its autonomous security institutions while negotiating their relationship with Baghdad. The Peshmerga remain a significant ground force, and the United States has long worked with Kurdish forces as part of the wider campaign against ISIS. The original coalition transition plan explicitly envisaged continued support for Iraqi forces, including the Peshmerga, while moving toward a long-term bilateral security relationship. But training and battlefield cooperation are not substitutes for an integrated national air-defence architecture.

The strategic vulnerability is therefore not necessarily that the Peshmerga cannot defend the Kurdistan Region against a conventional ground invasion. The more immediate vulnerability lies in the changing character of warfare. Drones, ballistic missiles, cruise missiles, electronic warfare and precision strikes can bypass many traditional defensive advantages. A region can possess a substantial ground force and still remain exposed to aerial attack. The Kurdistan Region's security problem is consequently moving from the traditional question of territorial defence toward the more complex question of integrated air and missile defence.

Iran's relationship with Iraqi Kurdistan makes this especially significant. Tehran has long objected to the presence of Iranian Kurdish opposition groups in the Kurdistan Region and has also regarded the presence of American forces in Iraq as a strategic threat. Barzani has acknowledged that Iranian officials have repeatedly raised both issues. From Tehran's perspective, the departure of American forces could remove one of the most important constraints on its ability to pressure Kurdish actors. From Erbil's perspective, however, the disappearance of the American military presence could leave the region more exposed precisely because it has historically maintained close relations with Washington.

This creates a difficult strategic choice for the Kurdish leadership. The Kurdistan Region cannot simply substitute Iran for the United States, because its relationship with Tehran is constrained by Iran's opposition to Iranian Kurdish groups operating from Iraqi territory and by the broader geopolitical relationship between Tehran and Washington. Nor can Erbil assume that Washington's political relationship will automatically produce the military protection that existed during the coalition period. The likely consequence is a greater emphasis on political risk management, regional diplomacy and attempts to construct multiple security relationships rather than relying on a single external guarantor.

The American withdrawal therefore represents a test of Kurdish strategic autonomy. For years, the presence of the United States allowed the Kurdistan Region to combine political autonomy with dependence on an external security provider. That arrangement was never permanent. The withdrawal exposes the need for Erbil to develop a more sustainable security model based on stronger internal coordination, closer federal security cooperation where possible, diversified international partnerships and greater investment in indigenous defensive capabilities.

The timing is particularly difficult because Kurdish internal politics remain divided. Relations between the Kurdistan Democratic Party and the Patriotic Union of Kurdistan have complicated the formation of a new regional government, while disputes over security institutions have historically limited the full integration of the Peshmerga. The recent emphasis on Peshmerga unification under the Ministry of Peshmerga Affairs is therefore strategically more important than an administrative reform alone. A more unified Kurdish security institution would give Erbil greater institutional capacity at precisely the moment when external military protection is declining.

But Peshmerga reform cannot solve every problem. Even a unified Kurdish force would require sophisticated intelligence, surveillance, air-defence, electronic warfare and logistical capabilities to respond effectively to modern missile and drone threats. Those capabilities require money, technology and long-term international partnerships. They also require a political agreement between Baghdad and Erbil over who controls, funds and deploys them.

The Baghdad-Erbil relationship is consequently moving back toward the centre of Iraq's strategic equation. The 2017 independence referendum and its aftermath weakened Kurdish bargaining power with Baghdad, including over disputed territories and energy. The Kurdistan Region's growing dependence on the federal budget has further increased Baghdad's leverage. At the same time, the federal government cannot indefinitely treat Kurdish security as a regional issue separate from Iraqi national security. A missile launched at Erbil is not simply an attack on the KRG; it is an attack on Iraqi territory.

This creates a potential opening for a new Iraqi security compact. Baghdad could use the post-withdrawal period to integrate Kurdish defence requirements into a genuinely national security strategy. Such an approach would not require eliminating Kurdish security institutions. Instead, it could establish clearer divisions of responsibility: federal authority over national defence and strategic airspace, coordinated Peshmerga responsibility for territorial security, and joint mechanisms for intelligence, counterterrorism and aerial threat detection. The success of such a model would depend less on constitutional language than on sustained political trust.

The alternative is a fragmented security order in which Baghdad formally controls national defence, Erbil retains significant autonomous security structures, armed groups retain independent military capabilities, and Iran retains substantial influence over Iraqi political and security networks. Such an arrangement could produce a state that is sovereign in legal terms but fragmented in strategic practice. The US withdrawal would then have completed the removal of one external military actor without resolving the underlying distribution of power.

There is also a lesson from the history of ISIS. Kurdish Prime Minister Masrour Barzani has warned that Washington risks repeating the circumstances surrounding the 2011 US withdrawal, after which ISIS eventually exploited political and security weaknesses before the United States returned to Iraq in 2014. The comparison should be treated carefully. Iraq in 2026 is not Iraq in 2011, and ISIS no longer controls the territory it once held. The United States and Iraq themselves describe the current transition as an evolution toward bilateral security cooperation rather than a simple abandonment of the country.

Nevertheless, the historical lesson is relevant at the level of institutional capacity. Military organisations do not become strategically self-sufficient merely because foreign forces leave. Intelligence networks, air surveillance, logistics, command integration and counterterrorism capabilities require years of development. The real measure of the withdrawal will therefore not be what happens on October 1, but whether Iraqi institutions can maintain security during the years that follow.

For Washington, the withdrawal also creates a credibility question beyond Iraq. The United States has spent decades building relationships with Kurdish political and security actors. The American presence in Erbil became an important symbol of that relationship, reinforced by the scale of the US diplomatic infrastructure there. The end of the military mission does not necessarily mean the end of American influence. Washington can maintain significant diplomatic, economic and intelligence relationships with Iraq without permanent combat forces. But the distinction between political partnership and military commitment will become much clearer after September 30.

For Iran, meanwhile, the strategic environment is changing in the opposite direction. The removal of American forces reduces the direct military footprint of Tehran's principal adversary in Iraq. Yet Iran's influence will still face constraints. Baghdad has its own national interests, Kurdish political actors have their own calculations, and Iraq's economic and diplomatic relationships extend far beyond Iran. The withdrawal therefore does not automatically produce an Iranian-controlled Iraq. It creates a different contest in which influence will increasingly depend on political networks, economic relationships, armed groups, diplomacy and the ability of the Iraqi state to impose its authority.

The most important question after September 30 will therefore be whether Iraq can transform the end of the coalition mission into the beginning of a more coherent national security system. Baghdad's declaration of sovereignty will have strategic meaning only if sovereignty is accompanied by capability. Erbil's security concerns will become manageable only if Kurdish defence is incorporated into that national capability rather than treated as a separate political problem. And Washington's departure will be sustainable only if bilateral cooperation can replace enough of the practical security functions previously provided by the coalition.

The American military presence in Iraq was never simply about American troops. It was part of a wider balance among Baghdad, Erbil, Tehran, Washington, the Peshmerga, Iraqi security forces and armed non-state actors. Its removal changes that balance. The central geopolitical question is therefore not whether the United States is leaving Iraq, but who will fill the strategic space created by its departure, and under whose rules?

For Iraqi Kurdistan, the answer will determine whether the post-American period becomes an opportunity for deeper integration into a stronger Iraqi state or a period of increased exposure to external pressure. For Baghdad, it will determine whether sovereignty becomes a functioning security reality or remains primarily a political declaration. For Iran, it will test whether influence can expand without producing a new regional backlash. And for Washington, it will test whether a partnership can survive the withdrawal of the military shield that made the partnership tangible.

September 30 is therefore not the end of America's relationship with Iraq. It is the beginning of a much more consequential experiment: whether Iraq can defend its sovereignty without reproducing the fragmented security order that made foreign military intervention necessary in the first place.

Author bio:

Dr. Pshtiwan Faraj is a researcher and geopolitical analyst focusing on Iraq, Kurdistan, Iran, Turkey and Middle East security. He is the founder of Kurdish Policy Analysis.