What to Know About the Attacks on U.S. Military Bases in the Middle East

In a series of videos posted on Telegram by a shadowy organization known as the Islamic Resistance in Iraq, drones belonging to Iranian-backed militias can be seen taking off from the desert floor and streaking into the distance. The videos are paired with ominous texts threatening further strikes and warning Iraqis to stay away from U.S. military bases in Iraq and Syria, the targets of the attacks. The location of the videos could not be independently verified by TIME, but metadata from the videos indicates that the videos were taken on days of confirmed attacks on U.S. military bases.

For more than six months, Iranian-backed groups have refrained from launching drones or rockets against U.S. forces in Iraq and Syria. But in the wake of Hamas’s Oct. 7 assault on Israel which left more than 1,400 people dead, this period of relative calm has come to a sudden halt. In just the past week, U.S. forces in Iraq and Syria have been attacked 13 times, Pentagon spokesperson Pat Ryder said at a press conference on Oct. 24. While the attacks have been largely intercepted by U.S. missile defenses, 24 U.S. troops have been injured, Ryder said. One U.S. contractor also died from cardiac arrest during a false alarm at an air base in Iraq.

While the U.S. has long sought to reduce its military forces in the Middle East, the repeated attacks by Iranian-backed groups complicate the U.S.’s presence in the region and underscores the risks of further escalation. 

Here’s what to know about the groups threatening or attacking U.S. forces in the region.

Who Are the Groups Attacking U.S. Military Bases?

Pentagon spokesperson Ryder said on Oct. 23 that the U.S. does not have any intelligence proving that Iran “explicitly ordered” the recent attacks. Even so, administration officials have not been shying away from pointing to Iran’s role in encouraging its proxies. One senior defense official told reporters on Oct. 23, “it's fair to say when you see this uptick in activity and attacks by many of these groups, there's Iranian fingerprints all over it.”

Across the Middle East, Iran has a network of proxy forces in Lebanon, Syria, Iraq, Yemen, Gaza and Bahrain. While many of the groups also have their own local agendas, they receive training, weapons and funds from Iran and bolster Tehran’s influence in the region.

Read more: Militant Group Hezbollah Is on the Sidelines of the Israel-Hamas War. Here’s What to Know

One network in particular, the Islamic Resistance in Iraq, has taken credit for at least 11 attacks on U.S. troops so far, according to the Washington Institute. The group first appeared in the aftermath of Hamas’s attacks on Israel, and is an umbrella organization for a number of key Iranian-backed groups in Iraq, says Michael Knights, an expert in militias in Iraq and Syria at the Washington Institute. The groups have come together under this banner “to signal unity but also to hide individual culpability for attacks” if they happen to kill an American, he says.

It is unclear precisely how many Iranian-backed groups operate in Iraq and Syria, experts say. “There's at least 10 or 20, if not many more groups between the Iraq-Syria border alone,” says Behnam Ben Taleblu, an Iran expert at the Foundation for Defense of Democracies. These groups pose a threat primarily to the 2,500 U.S. troops in Iraq and the 900 in Syria. But at least one Iranian-backed group in Iraq, the Righteous Promise Brigades, has threatened to attack U.S. forces in Kuwait and the United Arab Emirates.

What Happens if the Attacks Escalate?

The militia groups have been clear in linking their latest escalations to the U.S’s support for Israel. "The Americans are essential partners in killing the people of Gaza and therefore they must bear the consequences," Jaafar al Hussein, spokesman of Kataib Hezbollah, one of Iraq’s largest militia groups, wrote on Telegram on Oct. 18.

The attacks on U.S. military bases so far are the largest barrage of attacks since the Iranian response to the assassination of General Qasem Soleimani in January 2020, experts say. So far, the attacks have been small-scale rocket or drone strikes at military bases designed to withstand these kinds of attacks, says Knights, rather than large-scale attacks aimed at overwhelming air defenses and killing large numbers of U.S. forces.

Even so, experts say that if the attacks were to kill U.S. forces, the situation may escalate dramatically. “You don't launch rockets and missiles and armed drones into populated areas such as bases without a willingness to kill,” says Afshon Ostovar, an associate professor at the Naval Postgraduate School. “And if you're going to commit lethal attacks, the escalatory ladder or dynamic that follows is never a sure thing.”

Secretary of Defense Lloyd Austin said Sunday Oct. 22 that “what we’re seeing is a prospect of a significant escalation of attacks on our troops and our people throughout the region.”

If the groups decide to intensify the attacks on U.S. forces further, experts say that attacks on U.S. helicopters flying over Iraq or a return to the widespread usage of roadside bombs that killed thousands of U.S. troops in Iraq and Afghanistan could be likely strategies. 

The Houthi Threat

In the Red Sea, the USS Carney shot down several missiles and drones that were fired by Iranian-backed Houthi rebels on Oct. 19. U.S. officials say they were not fired at the American navy destroyer, but may have been aimed for Israel. Houthi leader Abdel-Malek al-Houthi warned shortly after Hamas’s attack on Israel that if the U.S. were to get directly involved in Gaza, that his group would respond with missiles and drones.

While the Houthi army is more than 1,400 miles from the Israel-Hamas war, they possess some of the most advanced capabilities of any of the Iranian-backed groups in the Middle East. “They are significantly ramping up their long range strike capabilities,” says Behnam Ben Taleblu of the Foundation for Defense of Democracies, “which allows them to be a more effective press against international shipping and American power in the Red Sea and Bab-el-Mandeb,” the narrow strait separating Yemen from East Africa.

In response to the rising threats, the U.S. is rushing air defense systems to its Middle Eastern military facilities and has tightened security around its bases. The U.S. has also sent a number of ships, including two aircraft carriers, and additional fighter jets to the region as it seeks to deter Iran and its allies from getting involved further.

“The United States does not seek conflict with Iran,” Secretary of State Anthony Blinken said at a tense meeting of the UN Security Council on Oct. 24. “But if Iran or its proxies attack U.S. personnel anywhere, make no mistake: We will defend our people, we will defend our security—swiftly and decisively.”