Battle of Baghuz Fawqani in the context of "Operation Inherent Resolve"

The Islamic State (IS) had its core in Iraq and Syria from 2013 to 2017 and 2019 respectively, where the proto-state controlled significant swathes of urban, rural, and desert territory, mainly in the Mesopotamian region. Today the group controls scattered pockets of land in the area, as well as other minor strongholds or underground insurgent cells in other areas, notably Afghanistan, West Africa, the Sahara, Somalia, Mozambique, and the Democratic Republic of the Congo. As of 2023, large swathes of Mali have fallen under IS control.

In early 2017, IS controlled approximately 45,377 square kilometers (17,520 square miles) of territory in Iraq and Syria and 7,323 km of territory elsewhere, for a total of 52,700 square kilometres (20,300 sq mi). This represents a substantial decline from the group's territorial peak in late 2014, when it controlled between 100,000 and 110,000 square kilometres (39,000 and 42,000 sq mi) of territory in total. IS territory has declined substantially in almost every country since 2014, a result of the group's unpopularity and the military action taken against it. By late March 2019, IS territory in Syria was reduced to only the besieged 4,000 km (1,550 sq mi) Syrian Desert pocket. The enclave was surrounded by Syrian government forces and its allies. The Syrian military conducted combing operations and airstrikes against the pocket, but with limited success. IS propaganda claims a peak territorial extent of 282,485 km.

The Deir ez-Zor campaign, codenamed the al-Jazeera Storm campaign, was a military operation launched by the Syrian Democratic Forces (SDF) against the Islamic State (IS) in Syria's Deir ez-Zor Governorate in 2017 during the Syrian Civil War with the goal of capturing territory in eastern Syria, particularly east and north of the Euphrates river. The U.S.-led Combined Joint Task Force – Operation Inherent Resolve (CJTF–OIR) anti-ISIL coalition provided extensive air support while SDF personnel composed the majority of the ground forces; OIR special forces and artillery units were also involved in the campaign.

The ground campaign stalled and was paused in early 2018 due to the Turkish military operation in Afrin, but resumed on 1 May 2018 with the new phase named by the coalition as Operation Roundup. The third phase began on 10 September 2018 but was halted due to Turkish artillery attacks on SDF positions near the Syria-Turkey border on 31 October. The SDF and the coalition announced the resumption of the offensive on 11 November. After a series of steady successes following the capture of ISIL's Hajin stronghold, and a ten-day pause for civilian evacuations, the SDF launched its final assault on ISIL's final pocket of territory on 9 February 2019 and declared victory on 23 March, concluding the campaign.