The White House on Tuesday warned Iran against attacks by its proxies in Iraq. The statement is a departure from previous US policy in Iraq which was not to confront the numerous Iranian-backed Shia militias operating in the country. Now Washington says it will hold Tehran accountable for any attack that results in injury to US forces or damage to US government facilities. The statement comes in response to threats to the US consulate in Basra.

In August, the US State Department rolled out a new Iran Action Group that is designed to pressure Tehran and coordinate actions across the US government. This coincided with President Donald Trump signing the 2018 National Defense Authorization Act that singled out Iran in numerous places.

Iran has been supporting a plethora of militias in Iraq since Tehran began to operate more openly among Shi’ites there following the US-led 2003 invasion that toppled Saddam Hussein. Groups such as the Badr Organization and Kata’ib Hezbollah are run by Iraqis who served alongside the Iran’s Islamic Revolutionary Guard Corps (IRGC) in the 1980s fighting against Saddam Hussein. During the war on Islamic State, Iranian-backed militias expanded their power in Iraq, helping to defeat ISIS. This put them on the same side as the US-led Coalition. Called the Popular Mobilization Forces or Hashd al-Shaabi, their numbers grew to almost 100,000 men under arms. However their deepening influence in Baghdad concerned Washington. In 2016 parliament in Iraq allowed the Iranian-backed militias to become an official paramilitary force. Former Secretary of State Rex Tillerson warned the militias to “go home.” However current Iraqi Prime Minister Haider al-Abadi told Tillerson last year that the Iranian-backed groups were the “hope” of Iraq and the region.

In the May 2018 elections in Iraq, these militias’ party, called the Fateh Alliance, came in second place. Since then the US has sought to bolster its allies and deny the Iranian-backed parties control of Baghdad. The recent protests in Basra have become part of these tensions between those in Iraq who want to be free of Iran’s overbearing influence and those who are close to Tehran. Protesters burned the Iranian consulate last week and targeted the headquarters of the Iranian-backed militias, including Badr and Kata’ib Hezbollah. Rockets were then fired at the US consulate.

The US statement holding Iran responsible for the attacks in Basra represents a major change in US policy. US officials reported in the spring of 2018 that “Iranian support for certain PMF militias posed the greatest threat to the safety of US personnel in Iraq,” according to a Department of Defense Inspector General Report in May. The White House now says that “Iran did not act to stop these attacks [on September 7] by its proxies in Iraq, which it has supported with funding, training and weapons.”

However the PMF have been incorporated into the Iraqi Security Forces, which means that their training and funding also comes from Baghdad. How to disentangle Baghdad from its alliance with Washington and its support of militias that threaten the US is now a major challenge for the Trump administration. US Vice-President Mike Pence also condemned the IRGC on Monday for a missile attack on Kurdish opposition groups in northern Iraq that killed 17 people in Koya. He called the attack an “effort to threaten and destabilize [Iran’s] closest neighbor.” Taken alongside the White House condemnation of Iranian proxies, the US is constructing a new policy in Iraq to confront Iran’s role in the country.