How the U.S. strikes a delicate balance in responding to attacks by Iran-backed militias on its forces

WASHINGTON – Iran-backed fighters in Iraq and Syria have long been fighting U.S. and coalition forces, carrying out sporadic attacks on bases in the region where troops are deployed to fight the Islamic State group’s insurgents.

However, since October 17, as the civilian death toll in Israel’s war with Hamas began to rise rapidly, there has been a dramatic increase in the number of attacks by Iranian proxies, collectively known as the Islamic Resistance Movement in Iraq.

Although most of the more than five dozen attacks were largely ineffective, at least 60 U.S. personnel reported minor injuries. The most common were brain injuries resulting from the explosion, and according to the Pentagon, all soldiers returned to duty.

The United States has walked a delicate line in response to the attacks. The U.S. military responded just three times as the Biden administration balanced efforts to deter militants without sparking a broader conflict in the Middle East.

A look at the attacks and the US response:

Attacks – when, where, why

According to the Pentagon, since October 17, Iranian-backed militants have carried out 61 attacks on bases and facilities housing U.S. personnel in Iraq and Syria. Of these, 29 took place in Iraq and 32 in Syria.

The United States has about 2,000 U.S. forces in Iraq under an agreement with the Baghdad government and about 900 in Syria, mainly to combat IS, but also uses the al-Tanf garrison further south to track Iranian proxies transporting weapons across the border.

The latest surge in attacks began 10 days after Hamas’ incursion into Israel on October 7, killing at least 1,200 people. Israel’s fierce military response has killed thousands of civilians trapped in Gaza and fueled threats of retaliation from a range of Iran-backed groups, including Hezbollah in Lebanon, Yemen’s Houthis and militants in Iraq and Syria. These threats intensified after the October 17 explosion at a Gaza hospital, which killed hundreds of civilians. Hamas blamed Israel for the explosion, but Israel denied it, and both Israeli and U.S. officials blamed it on an Islamic Jihad rocket misfire.

Most attacks on bases and facilities have occurred using single-directional suicide drones or missiles, and in most cases no injuries and only minor damage have occurred. A significant number of injuries, particularly traumatic brain injuries, occurred during the initial attacks on October 17–21 against al-Asad Air Base in Iraq and al-Tanf. One American contractor suffered a cardiac arrest and died while seeking shelter from a possible drone attack.

Who are these groups?

Facing a power vacuum and years of civil strife after the U.S.-led invasion of Iraq in 2003, militias in Iraq have grown and multiplied, some backed by Iran. Ten years later, as the Islamic State extremist group swept through Iraq, a number of Iran-backed militias united under the umbrella group of the Popular Mobilization Forces and fought against IS.

These groups included Asaib Ahl al-Haq, the Badr Brigades and Kataeb Hezbollah, or the Hezbollah Brigades – a separate group from Lebanese Hezbollah. A number of Iraqi militias also operate in Syria, where Iran is supporting Bashar Assad’s government against opposition groups in an uprising that turned into a civil war that began in 2011.

Following the outbreak of the Israel-Hamas war, a group of Iran-backed factions have signed on to the new name of the Islamic Resistance Movement in Iraq and launched the latest wave of attacks on bases housing US forces in Iraq and Syria.

The attacks put Iraqi Prime Minister Mohammed Shia al-Sudani in a difficult situation. Although he came to power with the support of Iran-backed groups, he also wants continued good relations with the US and supports the permanent presence of US troops in his country.

US Secretary of State Antony Blinken, in a meeting with al-Sudani this month, warned of consequences if Iran-backed militias continued to attack US facilities in Iraq and Syria. Al-Sudani then traveled to Tehran and met with Iran’s Supreme Leader Ayatollah Ali Khamenei, which US officials said was a positive development.

An official from one Iran-backed militia said al-Sudani put “great pressure” on the militias not to carry out attacks during Blinken’s visit. In return, he said, al-Sudani promised to urge the Americans not to take aggressive retaliation against the militias that carried out the attacks. The official spoke on condition of anonymity because he was not authorized to speak publicly.

Proportionate or insufficient?

Since the Oct. 7 Hamas attack, the Biden administration has moved warships, fighter jets, air defense systems and more troops to the Middle East as part of a campaign to discourage militant groups from expanding the conflict.

However, the United States military response to attacks on its forces was minimal. On October 27, U.S. fighter jets struck two arms and ammunition dumps in eastern Syria near Boukamal that were used by Iran’s Islamic Revolutionary Guard Corps and Iran-backed groups. On November 8, fighter jets dropped bombs on an IRGC weapons depot near Maysulun in Deir el-Zour. And on November 12, American airstrikes targeted a training center and a hideout in the Bulbul district of Mayadin. U.S. officials said IRGC-affiliated personnel were there and a possible strike occurred, but gave no details.

The administration has expressed concerns that more sweeping retaliation could escalate violence and trigger more deadly attacks. The Pentagon says the strikes destroyed the group’s military supplies and rendered the facilities unusable.

But critics say the U.S. response pales in comparison to the 60 attacks and injuries to Americans and, more importantly, has clearly failed to deter these groups.

The sensitivity of the Iraqi government

Although almost half of the attacks occurred against U.S. bases in Iraq, the United States only conducted retaliatory airstrikes on locations in Syria.

The Pentagon defends the decision to strike, claiming that the United States is striking Iranian Revolutionary Guard facilities, which has a more direct impact on Tehran. Officials say the goal is to pressure Iran to order militia groups to stop attacks. They also say the sites were chosen because they are weapons caches and logistical hubs used by Iran-linked militias, and their removal weakens the insurgents’ attack capabilities.

A key reason for the United States’ focus on Syria, however, is that the United States does not want to risk alienating the Iraqi government by striking within its borders – potentially killing or injuring Iraqis.

In early January 2020, the United States conducted an airstrike in Baghdad, killing Gen. Qassim Soleimani, head of Iran’s elite Quds Force, and Abu Mahdi al-Muhandis, deputy commander of Iran-backed militias in Iraq. The strike strained relations with the Iraqi government and prompted demands for the withdrawal of all American forces from the country.

The United States views its presence in Iraq as crucial to the fight against IS, its ability to support forces in Syria, and its continued influence in the region. Military leaders have worked to restore good relations with Baghdad, including providing continued support to Iraqi forces.