Most of Iraq’s paramilitary groups are members of the Popular Mobilization Forces (PMF), a collection of around 40 different Shiite militias consisting of over 150,000 armed fighters, who helped the Iraqi government defeat the Islamic State in 2017. The militias began to form in the summer of 2014, after Sayyid Ali al-Husseini al-Sistani, the spiritual leader of the Iraqi Shiite community, issued a fatwa (religious degree) that called or the destruction of the Islamic State. The Iranian-supported PMF proved instrumental in the territorial defeat of ISIS. However, the group’s leadership is ideologically aligned with Iran, and many of its members have called for the end of American military and diplomatic presence in Iraq.

In January of this year, many of these groups declared war on the United States, after Washington launched a drone strike that killed the Iranian general Qassem Soleimani and Abu Mahdi al-Muhandis, the leader of the Kita’ib Hezbollah (KH). KH is one of the most powerful Shia militias in Iraq, and controls much territory around the country. In a surprise move on Thursday, Iraqi counterterrorism forces announced they had arrested 14 members of KH, after receiving an intelligence tip. According to the government, the KH members were planning to launch large-scale attacks on Baghdad’s Green Zone, a heavily fortified area of the Iraqi capital that houses the headquarters of most ministries, as well as several embassies.

The arrests were reportedly ordered by Iraq’s new Prime Minister, Mustafa al-Kadhimi, former director of Iraq’s National Intelligence Service, who assumed his new duties on May 7. His appointment ended a prolonged political impasse, as the country had struggled to replace the government of his predecessor, Adil Abdul-Mahdi, who resigned in 2019 following a wave of popular protests. Al-Kadhimi is known to have good relations with Washington, while also being in good standing with Tehran. However, he vouched last month that he would “crush” the paramilitaries, who he views as enemies of Iraqi democracy.

In response to al-Kadhimi’s pronouncements, Shi’a militias have been launching constant small-rocket attacks targeting the Green Zone in recent weeks. Observers warned on Saturday that arrests of KH members have never been known to take place before, so this may be the opening shots of an open war between al-Kadhimi and Iraq’s Shi’a paramilitaries.