[184] With the arrival of the new Trump administration in January 2017, a change in policy was instituted regarding the disclosure of current troop levels as well as the timing of any additional deployments to the area, thus making good on his campaign promises to utilize the "element of surprise."

On Saturday, 9 August, U.S. forces launched 4 airstrikes against ISIL fighters threatening civilians on Mount Sinjar, this time primarily aimed at armored fighting vehicles.

[264] By the end of September 2014, the United States Navy and Air Force had conducted 240 airstrikes in Iraq and Syria, as well as 1,300 tanker refueling missions, totaling 3,800 sorties by all types of aircraft.

Sheikh Mahmud Nimrawi, a prominent tribal leader in the region, added that "U.S. forces intervened because of ISIL started to come near the base, which they are stationed in so out of self-defense," he responded, welcoming the U.S. intervention, and saying "which I hope will not be the last.

[278] By late February, it was reported that ISIL was beginning to use chemical weapons, due to the gradual weakening of the organization,[279] and that the Iraqi Army was expected to join the Liberation of Mosul sometime in April 2015.

[280] At the beginning of March, the Iraqi government announced that they would soon launch a military operation with the Kurdish Peshmerga and other allies to regain the city of Mosul, which was under ISIL control since 10 June 2014.

[283][284] That night, U.S. aircraft carried out 17 airstrikes in the center of Tikrit, which struck an ISIL building, two bridges, three checkpoints, two staging areas, two berms, a roadblock, and a command and control facility.

[306] In late-February, U.S. special forces captured Sleiman Daoud al-Afari, an ISIL senior chemical weapons engineer, in a raid in Badoosh, north-west of Mosul, there were no U.S. casualties.

[338] On 28 September, The New York Times reported that U.S. officials said President Obama had authorized the sending of an additional 600 U.S. troops to Iraq to assist Iraqi forces in the upcoming battle to retake Mosul from IS.

An Iraqi general told The Associated Press that later that day, Iraq's special forces entered the outskirts of Mosul, taking the state television building and advancing to the borders of Karama district despite fierce resistance by IS fighters.

"[349] On 27 January Sky News reported that French special forces in Mosul discovered a warehouse and unloading area near the Tigris River where dozens of missiles were stored alongside makeshift launchers with Russian markings.

The weapons are thought to have come from Syria, most were designed to be fired by jets but one was a 10 ft-long missile- beneath the cover of trees IS fighters had been working on building a Scud missile.

[351] On 11 February, the Telegraph reported that Iraqi aircraft carried out an airstrike on a house in Anbar where ISIL leader Abu Bakr al-Baghdadi was holding a meeting with senior ISIS commanders, killing more than a dozen.

[361] Reuters reported that Iraqi State TV said that, citing Iraq's military intelligence, an air strike in the region of al-Qaim killed Ayad al-Jumaili, who was believed to be the "second-in-command" of ISIL.

[362] On 29 April, Army Times reported that First Lieutenant Weston Lee of 1st Battalion, 325th Infantry Regiment, 2nd Brigade Combat Team, 82nd Airborne Division died from wounds received from the detonation of an IED during a patrol outside Mosul.

On 22 December, Australian Defense Minister Marise Payne said that Australia will end air strikes against ISIL and bring its six Super Hornet planes back home.

[375] PMU spokesman Ahmed Al Asadi confirmed the death of Quds Force Commander Qasem Soleimani in an airstrike, blaming Israel and the United States.

[379] On 7 January, Iraqi Prime Minister Abdul Mahdi held a Cabinet meeting, where he declared his support for a removal of foreign troops and stated that it was the only way to de-escalate growing tension[119][120] This drew further objection from the U.S.

[405] In early July 2020, a Katyusha rocket launched from the Ali al-Saleh area of Baghdad towards the Green Zone injured a child and damaged a house after it landed south of its target.

[406] On 27 January 2021, during a joint operation led by the Iraqi Counter Terrorism Service (CTS), the coalition killed ISIL's leader in Iraq, Abu Yasser al-Issawi, in an air strike on an underground hideout in Kirkuk.

[410] The United Kingdom made humanitarian supply airdrops to Yazidi refugees on Mount Sinjar starting on 10 August 2014,[411][412] using Royal Air Force C-130's operating from RAF Akrotiri in Cyprus, while surveillance was provided by Panavia Tornado GR4s.

[415] On the night of 13–14 August, a 16-aircraft mission including U.S. C-17s and C-130Hs, a British C-130J, and an Australian C-130J airdropped supplies to Yezidi civilians trapped on Mount Sinjar in what was later described as "the first mass air delivery of humanitarian cargo since the outbreak of violence in East Timor in 1999.

"[443][needs update] An article by the Associated Press wrote that critics of Obama drew a direct connection between his foreign policy approach that underestimated ISIS and his decision to withdraw all American troops from Iraq in late 2011.

Two editorials by The Washington Post argued that Iraqi's disintegration would threaten national, regional and global security[449] and described efforts by the Obama administration to create a more inclusive Iraq government as presenting the best hope for the country in its fight against ISIS.

[453] Similarly, an editorial in The Wall Street Journal written in August wrote of the strategic interest the United States had in defeating ISIL and positively assessed the efficacy of American airstrikes in "reducing the jihadists' room for maneuver and giving new confidence to the Kurdish forces.

An editorial in The Washington Post criticized the American strategy of creating a unity government in order to fight ISIL was a mirage due to the country's political-religious cleavages and ISIS's numerical and technological superiority.

Specifically, he argued that: the government in Baghdad invited international forces to join in the fight against IS; the newly reconstituted and religiously representative Iraqi government has a positive obligation to deliver on its constitutional promises and defend its population from subjugation by ISIS; and foreign intervention exercising the right of collective self-defense on behalf of Iraq can involve forcible action in IS-controlled territories in Syria that is proportional to the necessity of securing Iraq's borders.

[458] Similarly, Michael Ignatieff, professor of politics at Harvard University discussed the international dimensions of American intervention in Iraq in an interview with Der Spiegel in which he described the Islamic State as an "attack on all values of civilization" and that it was essential that America, "continued with their air strikes.

[460] On the other hand, Aaron Zelin of the Washington Institute for Near East Policy argues that ISIL are "likely planning attacks whether the U.S. conducts targeted air strikes or not" and that, in his opinion, the United States, "should destroy them as soon as possible.

"[463] An editorial in Vox defined the intervention as being limited to Kurdistan, effectively allowing the Islamic State to control a large part of Iraq absent any other occupying power.