Israel attacked military targets in Iran with pre-dawn air strikes on Saturday in retaliation for the barrage of ballistic missiles the Islamic Republic fired on Israel earlier this month.
The strikes marked the first time Israel’s military has openly attacked Iran.
Following the air strikes, Iran’s Foreign Ministry said it had a right to self-defence, and “considers itself entitled and obligated to defend against foreign acts of aggression”.
Foreign minister Abbas Araghchi said Iran has “no limits” in defending its interests.
But late on Saturday, Iran’s military issued a carefully worded statement suggesting any ceasefire in Israel’s ground offensives in the Gaza Strip and Lebanon would trump any possible retaliatory strike.
Israel’s military said it targeted facilities that Iran used to make the missiles fired at Israel as well as surface-to-air missile sites.
There was no immediate indication that oil or nuclear sites were hit, which would have marked a much more serious escalation.
Iran’s state-run IRNA news agency said four people were killed, all with the country’s military air defence.
Iran’s military said the strikes targeted military bases in Ilam, Khuzestan and Tehran provinces, without elaborating.
The Islamic Republic said the attacks caused “limited damage”.
The strikes risk pushing the archenemies closer to all-out war at a time of spiralling violence across the Middle East, where militant groups backed by Iran – including Hamas in Gaza and Hezbollah in Lebanon – are already at war with Israel.
US President Joe Biden told reporters Israel gave him a heads-up before the strikes and said it looked like “they didn’t hit anything but military targets”.
He said he had just finished a call with intelligence officials.
“I hope this is the end,” Mr Biden said.
Iran had not faced a sustained barrage of fire from a foreign enemy since its 1980s war with Iraq.
On October 1, Iran launched at least 180 missiles into Israel in retaliation for devastating blows Israel landed against Hezbollah.
They caused minimal damage and a few injuries.
Prime Minister Benjamin Netanyahu said Iran “made a big mistake”.
Israel is also widely thought to be behind a limited air strike in April near a major air base in Iran that hit the radar system for a Russian-made air defence battery.
Iran had fired a wave of missiles and drones at Israel in April, causing minimal damage, after two Iranian generals were killed in an apparent Israeli air strike on an Iranian diplomatic post in Syria.
“Iran attacked Israel twice, including in locations that endangered civilians, and has paid the price for it,” Israeli military spokesperson Rear Admiral Daniel Hagari said.
He added: “If the regime in Iran were to make the mistake of beginning a new round of escalation, we will be obligated to respond.”
Images released by Israel’s military showed members preparing to depart for the strikes in American-made F-15 and F-16 warplanes.
The Iranian military statement described Israel’s warplanes as firing lightweight missiles at a distance of 100 kilometres (62 miles) from the Iranian border.
The missiles struck air defence radar stations, the Iranian military said, some of which were already under repair.
However, Iran’s paramilitary Revolutionary Guard – which oversees its vast arsenal of ballistic missiles – has remained silent since the attack, raising questions about whether anything had been hit at its bases.
The Guard is one of the main power centres within Iran’s theocracy, as its regular military has been shunted aside since the 1979 Islamic Revolution.
Israel’s attack did not take out highly visible or symbolic facilities that could prompt a significant response from Iran, said Yoel Guzansky, a researcher at Tel Aviv’s Institute for National Security Studies who formerly worked for Israel’s National Security Council.
It also gives Israel room for escalation if needed, and targeting air defence systems weakens Iran’s capabilities to defend against future attacks, he said, adding that if there is Iranian retaliation, it should be limited.
Israel has again shown its military precision and capabilities are superior to Iran’s, said Sanam Vakil, the director of the Middle East and North Africa programme at the London-based think tank Chatham House.
“By targeting military sites and missile facilities over nuclear and energy infrastructure, Israel is also messaging that it seeks no further escalation for now,” Ms Vakil said.
“This is a sign that the diplomacy and back-channel efforts to moderate the strike were successful.”
Mr Biden’s administration won assurances from Israel in mid-October that it would not hit nuclear facilities and oil installations.
After the strikes, the streets in Iran’s capital were calm and children went to school and shops opened.
There were long lines at petrol stations – a regular occurrence in Tehran when military violence flares as people stock up on fuel.
But some Tehran residents seemed anxious and avoided conversations with an Associated Press reporter.
Israel’s opposition leader Yair Lapid criticised the decision to avoid “strategic and economic targets”, saying on X that “we could and should have exacted a much heavier price from Iran”.
The United States warned against further retaliation, and Britain and Germany said Iran should not respond.
“All acts of escalation are condemnable and must stop,” the spokesman for the UN secretary-general said.
Saudi Arabia was one of multiple countries in the region condemning the strike, calling it a violation of Iran’s “sovereignty and a violation of international laws and norms”.
Both Hezbollah and Hamas condemned Israel’s attack, with Hezbollah saying it would not affect Tehran’s support for Lebanese and Palestinians fighting Israel.
