The United States formally ended Operation Inherent Resolve on Wednesday, completing the withdrawal of all military forces from Iraq after a 12-year campaign against ISIL. Other coalition partners also departed by the September 30 deadline set two years earlier by Washington and Baghdad. For Iraq's Kurdish Peshmerga — who relied on US air cover, intelligence sharing, and hardware for three decades — the departure strips away the most reliable security guarantee they have known. Days before the withdrawal, on September 21, the Kurdistan Regional Government announced the merger of armed factions affiliated with the Kurdish Democratic Party and the Patriotic Union of Kurdistan into a single unified force. KRG President Nechirvan Barzani framed it as existential: "Kurdistan needs one force, one ministry, and one command." He warned that the post-unification phase "may be even more difficult" than the struggles that preceded it. The merger addresses a structural weakness that has persisted since the KDP-PUK civil war of the 1990s. Two geographically distinct commands — Erbil-based KDP forces and Sulaymaniyah-based PUK forces — have operated as parallel armies under a shared ministry. Zeidon Alkinani of the Arab Perspectives Institute told Al Jazeera that Iraq's most damaging rivalries have been intra-community, not inter-community, and that reducing party structures within the Peshmerga "strengthens Iraq's stability and gives Erbil firmer legal footing with Baghdad." Retired Lieutenant General Jabbar al-Yawar cautioned that ongoing political disputes over Kurdistan's governance and its relationship with Baghdad could easily infect military institutions if party ties persist. The Ministry of Peshmerga insists readiness is not in question. Spokesperson Major General Othman Mohammed pointed to the Peshmerga's 2014 performance against ISIL with limited means and described "very good cooperation and coordination" with Iraqi federal security forces. But Mohammed Salih of the Foreign Policy Research Institute says "considerable uncertainty and concern" exists among Kurds about whether the US departure signals the end of Washington's commitment to Kurdish security — a commitment that has functioned as a de facto umbrella for three decades. Critically, the US took key air defence systems with it when it withdrew, creating a tangible capability gap for Erbil. The Kurdistan region has endured multiple drone and missile attacks since the US war on Iran began, and without coalition air defences, Erbil is exposed in ways it has not been since the 1990s. This is not an abstract concern — it is a hardware deficit with immediate operational consequences. The withdrawal may, paradoxically, ease one of Iraq's sharpest internal tensions. Iran-aligned Iraqi armed groups had pointed to the US military presence as justification for their own refusal to disarm. With US troops gone, that argument evaporates. KDP leader Masoud Barzani publicly backed Baghdad's efforts to fight corruption, disarm Iran-aligned militias, and settle disputes with Erbil under the constitution. Alkinani noted that Iraqi federalism depends on "communication, coordination and respect for the rule of law among political parties, not on foreign troops" — but added the caveat: "only if Iraqis replace it with dialogue and law rather than force." The next 12-24 months will reveal whether Peshmerga unification is structural or ceremonial. If the two commands genuinely integrate — shared intelligence, unified logistics, joint command authority — the Kurds emerge with a stronger negotiating position vis-à-vis Baghdad and a more credible deterrent. If party loyalty reasserts itself under stress, the merger becomes a press conference, and the security vacuum left by the US departure becomes an invitation.
