The attack on US troops in Iraq, explained

On Monday, an attack on the al-Asad airbase in Iraq wounded at least five American military servicemembers and two contractors. The attack could be an isolated incident, but there are signs that it may be part of a broader escalation in the region.
The strike comes amid a period of escalating violence in the Middle East. Israel is still waging its war in Gaza, and is believed to have also recently assassinated Hamas’s political leader, Ismail Haniyeh, and Hezbollah military commander Fuad Shukr in Iran and Lebanon respectively. Iran, which backs both Hamas and Hezbollah, has blamed Israel for the attacks, and is widely expected to retaliate. Now, uncertainty over how Iran will respond has raised the possibility of wider conflict in the region.
It’s unclear if Iran had anything to do with the attack on al-Asad, and no group has claimed responsibility as of yet. There are Iran-allied groups operating in Iraq, such as the prominent Iraqi militia Kataib Hezbollah. But even if one of these groups is behind the strike, that doesn’t necessarily mean it was on Iran’s orders; Iran’s allies in Iraq sometimes act without explicit instruction.
But whatever the calculus behind Monday’s attacks, they are a reminder of just how easily the Israel-Gaza conflict could escalate — and spiral out of control.
Though Iraq’s president, Mohammed Shia al-Sudani, announced in January that he aimed to kick US troops out of his country, there are still roughly 2,500 American troops in Iraq, who are part of a mission to fight the Islamic State.
US forces recently targeted militias, known as Popular Mobilization Forces (PMFs), that they accused of plotting to launch drones in a threat to US installations.
The PMFs are often referred to as Iran-backed — and they do have support from Iran, though the story is a bit more complicated than that. Though Iran funds and equips militia groups in Iraq, they are not as closely aligned with the Islamic Republic as Hezbollah in Lebanon, and have their own objectives.
And the PMFs are technically part of the Iraqi military. They were critical to the fight against ISIS, particularly early on in the conflict, as a recent report from the RAND Corporation notes. However, they do carry out attacks that further Iran’s foreign policy goals — to defeat Israel and get the Americans out of the Middle East. For example, these groups have been launching rocket attacks against US installations since about 2020, after the US’s assassination of Qasem Soleimani, a revered leader in the Iranian military, though some occurred as early as 2019.
So while Monday’s attack can be seen as a tit-for-tat response for the US attack last week, which killed four people, it could also potentially be part of Iran’s response to the assassinations of Haniyeh and Shukr. That’s especially true given Haniyeh was killed inside Iran, a fact that has embarrassed the country and its security forces. And though Iran has blamed Israel for the attacks, the country’s leaders see the US as complicit as well, due to the strength of the American-Israeli alliance.
Whether Iran can respond in a way that convinces Israel and the US to stand down rather than continue to escalate is the question, Colin Clarke, a senior research fellow at the Soufan Center, told Vox.
“I think that’s the challenge for the Iranians, is trying to thread that needle where they respond in a way that doesn’t prove to be completely impotent and reveal them as weak, but they also don’t want to go overboard.”
Too strong a response could provoke further violence from Israel, and potentially the US, putting the world in danger of an even larger war. But judging Israel and the US’s ability to stomach an Iranian response is increasingly difficult, Ali Vaez, director of the Iran program at the International Crisis Group, told Vox.
“I think that’s where the risk primarily lies, because [Iran feels that] without inflicting pain, there is no gain deterrence-wise, and Israel is not a country that just absorbs pain and does not respond — even with US arm twisting,” Vaez said.
Fears of a region-wide war began with Hamas’s October 7 attack on Israel, and have continued as regional powers have engaged in what’s known as “rocket diplomacy”; essentially, carefully calibrated attacks meant to send a message.
In the case of the air base attack, Vaez said the message could be that “if [the US] fails to hold Israel back after Iran retaliates for Haniyeh’s killing in Tehran, that the US would also be caught in a crossfire this time around.”
How Iran and its allies respond to the recent assassinations will help determine how big the conflict gets, and whether the equilibrium of violence in places like Lebanon — where Israel and Hezbollah have been trading rocket fire over Lebanon’s southern border, and where Israeli jets produced a sonic boom over Beirut — is broken.
Any Iranian response to the killings of Haniyeh and Shukr would probably rely on Iran’s regional partners overwhelming Israel’s Iron Dome defense system with rocket fire, so that at least some munitions get through and cause some real damage — perhaps even casualties.
“Let’s say they end up killing large numbers of Israeli civilians in a missile or rocket attack, which is possible, if the Iron Dome is overwhelmed and malfunctions,” Clarke said. “If they escalate too much, the Israelis are really going to continue, especially Netanyahu, to pressure the United States to become more involved, which is not a good scenario for the Iranians.”
And, according to Vaez, that’s a real possibility, with “a more sophisticated, multi-layered strategy from the Iranian side.”
Under that scenario, strikes and counterstrikes would likely continue — and the death toll would rise, in Iran, among its allied groups, and perhaps in Israel as well.