Patriot systems
© AP/Ranier Jensen
US Patriot surface to air missile system
On 10 March, General Kenneth McKenzie, chief of the US Central Command, said in an apparent reference to the Patriot interceptors, that the Pentagon is in the process of delivering its "air defence systems" to Iraq.

The Middle East Eye news outlet quoted unnamed sources as saying on Monday that the US military had deployed its Patriot missile defence system to the Ain al-Asad base in the western Iraqi province of Anbar.

According to the sources, the system is currently being assembled amid reports that the Pentagon plans to send two more Patriot batteries to an undisclosed location in Iraq. Baghdad has not yet commented on the matter.

The reported deployment comes after General Kenneth McKenzie, commander of the US Central Command, told the House Armed Services Committee on 10 March that the American military is sending its air defences to Iran [sic Iraq] , a few months after an Iranian missile attack on the Ain al-Asad base. In an apparent nod to the Patriot interceptors, McKenzie said:
"We are in the process of bringing air defence systems, ballistic missile defence systems into Iraq - particularly to protect ourselves against another potential Iranian attack."
The statement followed Defence Secretary Mark Esper saying in late January that the US was working on delivering Patriot systems to Iraq in the wake of Iran's missile attack, but that Washington needed "permission" from the Iraqi government to do so.

Joint Chiefs Chairman Mark Milley confirmed at the time that the US was "working with the Iraqi government" on the issue, adding that "the mechanics of it all" still needed to be worked out.

Iran Stages Missile Attack on US Bases in Iraq in Response to Soleimani Killing

On 8 January, Iran launched several dozen missiles at US military bases in Iraq, hitting the Erbil Airbase in the country's north and the Ain al-Asad Airbase west of Baghdad.

Iran reportedly provided advance warning to Iraq, which in turn presumably briefed the US forces stationed in the country, allowing them to take shelter in prepared bunkers. Although the missile strikes did not kill any US troops, they did cause substantial damage to base infrastructure.
The strikes came in response to the US assassination of Maj. Gen. Qasem Soleimani, head of Iran's Islamic Revolutionary Guard Corps' elite Quds force, on 3 January, when a drone attack authorised by President Trump hit the Iranian general's car at Baghdad International Airport.

The commander's killing further exacerbated Washington-Tehran tensions, which have been simmering since the White House's unilateral withdrawal from the 2015 Iran nuclear deal, or the Joint Comprehensive Plan of Action (JCPOA), and reinstatement of the US' anti-Iran sanctions in May 2018.

Iraq's parliament, for its part, voted to expel the estimated 5,000 US troops stationed in the country following Soleimani's assassination, but US officials have repeatedly ruled out a total withdrawal.

White House National Security Adviser Robert O'Brien said that the US would exit from Iraq "on its own terms", while President Trump demanded that the country pay the US back for a multi-billion-dollar airbase, threatening Baghdad with sanctions which he said would make those placed against Iran "look pale in comparison".