The US military has launched airstrikes on two locations in eastern Syria linked to Iran’s Revolutionary Guard Corps (IRGC), signalling a new willingness in Washington to engage its forces directly in the crisis in the Middle East.
The strikes, which the Pentagon said hit a weapons storage facility and an ammunition storage facility used by the IRGC and militia it backs, were the first such US military intervention since war broke out between Hamas and Israel on 7 October.
US facilities in Iraq and Syria have been hit by a series of low-level attacks by drones and rockets over the past 10 days that have been claimed by Iran-backed militia, amid growing fears that the Hamas-Israel war could escalate into a regional conflict.
The attacks have injured at least 24 US servicemen and the death of one civilian contractor. There were three such attacks on Thursday, striking two US bases in Syria and one in western Iraq.
Experts told the Guardian this week there was “a limit to patience” in Washington and that the administration of President Joe Biden would probably seek to deter with force any further attacks despite the risk of escalation.
Biden has already ordered two aircraft carriers to the eastern Mediterranean and sent new anti-missile units with hundreds of troops to protect US bases and allies in the region.
The US retaliatory strikes were carried out by two F-16 fighter jets at about 4.30am on Friday near Abu Kamal, a Syrian town on the border with Iraq, where the US has a major base that has been the target of several recent attacks by Iran-backed militia. It was unclear if Iranian nationals were killed.
The US defence secretary, Lloyd Austin, described “self-defence strikes” and said Biden had directed the tailored strikes “to make clear that the United States will not tolerate such attacks and will defend itself, its personnel, and its interests”.
US officials said they did not coordinate the strikes with Israel, and Austin said the operation was separate and distinct from Israel’s war against Hamas. He added: “We continue to urge all state and non-state entities not to take action that would escalate into a broader regional conflict.”
A week ago, a US warship intercepted missiles fired by Iran-backed Houthi rebels in Yemen, possibly at Israel.
The recent attacks on the US have been claimed by groups either directly controlled by Tehran or sharing the ideology of other groups fighting Israel. On Thursday, a US base at Kharab al-Jir in Syria was attacked for the second time in two days, and a base in western Iraq was also hit.
Iran’s foreign minister, Hossein Amir-Abdollahian, said at the UN on Thursday that if Israel’s offensive against Hamas did not stop, the US would “not be spared from this fire”.
Charles Lister, the director of the Syria and countering terrorism and extremism programmes at the Middle East Institute in Washington, said the attacks showed Iran had an extensive network of well-armed, aggressive and well-coordinated proxies across the region, “which it has established for exactly this scenario”.
He added: “They are currently testing redlines but not pushing too hard. They are putting the onus on the US to respond.”
The US is in a delicate situation. It wants to hit Iranian-backed groups suspected of targeting the US as strongly as possible to deter future aggression, while also trying to avoid inflaming the region and provoking a wider conflict.
One Iraq-based and Iran-supported group, believed to be a front for the long-established Kata‘ib Hezbollah, last week issued a statement threatening attacks on US military bases in the UAE and Kuwait. Paramilitaries from militia in Syria that are controlled by Iran have been deployed close to the Golan Heights, in a further threatening move.
On Wednesday, leading officials of the three principal Islamist extremist groups at war with Israel met in Beirut to discuss the conflict.
After the meeting, a brief statement said Hezbollah’s leader, Hassan Nasrallah, had agreed with Hamas’s Saleh al-Arouri and Palestinian Islamic Jihad’s leader, Ziyad al-Nakhalah, that the three – along with other Iran-backed militants – wanted to achieve “a real victory for the resistance in Gaza and Palestine” and halt Israel’s “treacherous and brutal aggression against our oppressed and steadfast people in Gaza and the West Bank”.
Tobias Borck, a senior research fellow in Middle East security studies at London’s Royal United Services Institute, said Iran was “literally playing with fire”.
“What we are seeing is the next level out from the Gazan war. This is all carefully calibrated to show solidarity. Iran is saying: we see the aircraft carriers but we are not scared and we can hurt you too. It is incredibly dangerous,” Borck said.
Earlier on Thursday, Biden also sent a rare message to the Iranian supreme leader, Ayatollah Ali Khamenei, warning Tehran against targeting US personnel in the Middle East, the White House said.
Governments in the west and the Middle East are concerned about a wider regional conflict developing if Israel continues its bombardment of Gaza or mounts a ground invasion in response to the 7 October attack by Hamas.
On Thursday, Israel said it was entering the “next stages of the war” after a substantial but limited raid on Gaza, in what was described as a probing action in preparation for a more sustained ground offensive.
Israel has imposed a siege on the densely populated Gaza Strip after the Hamas attack on Israeli communities 7 October that killed 1,400 people, including children, and took more than 200 hostages, some of them infants and older adults.
The Hamas-controlled Gaza health ministry said on Thursday that 7,028 Palestinians had been killed in the retaliatory airstrikes, including 2,913 children.
Satellite images released on Thursday by Maxar Technologies and Planet Labs show buildings in wide areas of the coastal enclave reduced to rubble and grey ash spread over the land.
Leaders of the 27 EU member states unanimously called for “humanitarian corridors and pauses” of the shelling in Gaza to allow in food, water and medical supplies.
The question of whether to have humanitarian pauses or ceasefire agreements in the Hamas-run coastal enclave will come before the 193-member UN general assembly on Friday in a draft resolution submitted by Arab states calling for a ceasefire.
Unlike in the security council where resolutions on Gaza aid failed this week, no country holds a veto in the general assembly. Resolutions are non-binding, but carry political weight.
Associated Press and Reuters contributed to this report
