Global Coalition to Defeat ISIS (Operation Inherent Resolve)

Overview

The Global Coalition to Defeat ISIS was announced by US Secretary of State John Kerry in September 2014, following the rapid territorial expansion of the Islamic State across Iraq and Syria in the preceding months. ISIL's seizure of Mosul in June 2014 and its declaration of a caliphate in June 2014 prompted a US-led response that eventually assembled approximately eighty member states from North America, Europe, the Middle East, the Asia-Pacific and elsewhere.

The coalition was assembled without a formal UN Security Council authorisation for the use of force, relying instead on the Iraqi government's invitation to coalition forces operating in Iraq and on claims of self-defence and collective security under Article 51 of the UN Charter for operations in Syria. This legal architecture was contested by some states and analysts but did not prevent coalition formation or operation.

The coalition's stated objectives were: the military defeat of ISIL's territorial presence; the disruption of ISIL financing, foreign fighter flows and propaganda; and the stabilisation and recovery of liberated areas.

Key Provisions

The coalition operates through a structure of working groups addressing its distinct lines of effort: military operations, foreign terrorist fighters, financing and economic disruption, stabilisation and humanitarian assistance, and counter-messaging. This structure recognises that military defeat of ISIL's territory was necessary but insufficient and that complementary non-military measures were required to address the broader dimensions of the ISIL phenomenon.

Combined Joint Task Force-Operation Inherent Resolve (CJTF-OIR) was formally established on 17 October 2014 as the military component of the coalition's operations in Iraq and Syria. The CJTF-OIR operated with US Central Command as the lead, with coalition member contributions including air assets, special operations forces, training and advising missions, intelligence sharing, logistics and other capabilities.

The coalition partnered with the Iraqi Security Forces, including the Kurdistan Regional Government's Peshmerga forces, in Iraq, and with the Syrian Democratic Forces (SDF), a Kurdish-led alliance, in Syria. These ground partnerships were essential to the territorial reconquest, as coalition policy did not include deploying large-scale ground combat units.

Implementation

Coalition operations began with airstrikes in Iraq in August 2014 and expanded to Syria in September 2014. The campaign to retake ISIL-held territory proceeded in stages, with major operations including the liberation of Sinjar (November 2015), Ramadi (December 2015), Fallujah (June 2016), Mosul (fully liberated July 2017), and Raqqa (October 2017).

ISIL's territorial control in Iraq was formally ended with the Iraqi government's declaration of liberation in December 2017. The final ISIL territorial holdout in Syria was eliminated at Baghouz on 23 March 2019, when SDF forces declared the capture of the last ISIL-held position.

The coalition's non-military lines of effort produced parallel outcomes. The flow of foreign fighters to ISIL-held territory, which had reached an estimated 40,000 from over 100 countries, was substantially reduced from 2015 onward through a combination of border security improvements, territorial loss reducing ISIL's attraction, and targeted counter-messaging. ISIL's financial revenues, derived from oil sales, taxation and extortion in held territory, were disrupted through air strikes on infrastructure and targeted financial sanctions.

Effectiveness and Criticism

The coalition achieved its primary stated objective: the territorial defeat of the Islamic State's caliphate. This is assessed as a significant military and political accomplishment, achieved more rapidly than many analysts expected when the coalition was formed.

Criticism has focused on several dimensions. The question of what follows territorial defeat has been persistent: ISIL transitioned from a territory-holding organisation to an insurgency operating in Iraq and Syria, and ISIL affiliates in other regions, including West Africa, East Africa, Afghanistan and elsewhere, remained active and in some cases grew following the loss of the core territory. Critics argued that insufficient attention was given to the post-liberation political environment, particularly in Iraq, where sectarian governance failures had contributed to ISIL's original rise.

The coalition's reliance on the SDF in Syria created a significant political tension with Turkey, a NATO member and coalition partner, which regarded the Kurdish forces at the SDF's core as a terrorist threat. This tension produced periodic crises in the coalition's political cohesion and military coordination.

Human rights organisations documented civilian casualties from coalition airstrikes that exceeded official coalition acknowledgments. Accountability for civilian harm from coalition operations has been criticised as inadequate.