Operation Inherent Resolve

Operation Inherent Resolve (OIR) is the operational name adopted by U.S. Central Command in October 2014 for the U.S.-led military campaign against the Islamic State of Iraq and Syria (ISIS, also called ISIL or Daesh). It encompasses airstrikes, special operations raids, intelligence sharing, and the "train, advise, and assist" mission supporting partner ground forces—primarily the Iraqi Security Forces (ISF), Kurdish Peshmerga, and the Syrian Democratic Forces (SDF).

The campaign operates under the broader Global Coalition to Defeat Daesh/ISIS, a political coalition launched in September 2014 that has grown to include dozens of states and international organizations. Legally, the U.S. executive branch has cited the 2001 Authorization for Use of Military Force (AUMF) against al-Qaeda and associated forces, as well as the 2002 Iraq AUMF, as domestic authority—an interpretation contested by many legal scholars and members of Congress. In Iraq, operations occur at the invitation of the Iraqi government; the legal basis for strikes in Syria is more contested and has typically been justified by Washington under the collective self-defense of Iraq.

Key milestones include the recapture of Tikrit (2015), Ramadi (2015–16), Fallujah (2016), Mosul (2017) after a nine-month battle, and Raqqa (2017), ISIS's self-declared capital. In March 2019, the SDF declared the territorial defeat of ISIS at Baghuz, Syria, though OIR continues counter-ISIS operations against insurgent remnants.

OIR has also been the framework under which U.S. forces have remained in Iraq and northeast Syria amid tensions with Iran-aligned militias and following Turkish incursions into northern Syria. In 2021, the U.S. and Iraq agreed to transition the American role in Iraq from combat to an advisory mission, and in 2024 the two governments announced plans to wind down the OIR coalition military mission in Iraq, with a phased drawdown extending into 2025–26.

For MUN delegates, OIR is often referenced in debates on counterterrorism authorizations, the law of armed conflict, sovereignty in Syria, and post-conflict stabilization.