The airstrikes
The strikes were carried out on September 23rd by two F/A-18F Super Hornets from the USS Nimitz, a spokesperson for the Bahrain-based US 5th Fleet told Stars and Stripes. The last similar strike on Iraq was by the USS Theodore Roosevelt in March of 2018 according to Commodore Rebecca Robarich.
Operation Inherent Resolve the anti-Islamic State (ISIS) coalition reported airstrikes on ISIS hideouts in Kirkuk Iraq on the same day so it is likely that these were the attacks carried out by the carrier-launched jets but Robarich did not confirm this and the paper Stars and Stripes was unable to confirm this either.
Airstrikes from carrier escalates anti-ISIS campaign
The USS Nimitz had transited the Strait of Hormuz entering the Persian Gulf with an accompanying strike force back on Sept. 18. The launching of airstrikes from the carrier has considerably increased the level of attacks against ISIS targets.
Nimitz patrol may be a message to Iran
Sending the Nimitz into Persian Gulf may be part of the Trump administration’s maximum pressure campaign on Iran. The patrol plus the airstrikes are no doubt meant as a show of force aimed at Iran.
US facilities have been attacked in Iraq
There have been a series of attacks on US bases and diplomatic compounds which house American and coalition personnel. There have been US responses usually against Iraqi militia often supported by Iran that the US has thought are responsible for the attacks. This has ramped up tensions with Iraq.
The US reportedly warned Iraq over the weekend that it was preparing to pull out of its embassy in Baghdad if Iraq does not do more to stop the attacks that US officials blame on Iran-backed militias. However, some of these militias are financed by the Iraqi government and are part of the Popular Mobilization Forces. Some time ago the Iraiqi parliament passed a motion that all foreign troops withdraw from the country. There is no sign that the US intends to withdraw all its troops or that the present pro-US Iraqi government intends to press the issue.
The US main rationale for being in Iran is to fight ISIS. However, the Islamic State has lost control of any territory and is quite weak. Iraqi could no doubt on its own counter any threat posed now by ISIS. However, the US would like to stay in Iraq to counter Iranian influence.