Israel carried out a series of airstrikes against Iran early Saturday, hitting multiple targets in a significant escalation of the conflict between the two sides that has sparked fears of a wider regional war.

The Israel Defense Forces (IDF) said in a statement that its offensive was in “response to months of continuous attacks from the regime in Iran,” adding that it had conducted “precise strikes on military targets.” Iran, meanwhile, appeared to downplay the impact of the strikes, saying that they caused “limited damage” and only killed a few soldiers.

In a statement on Saturday, U.S. Defense Secretary Lloyd Austin reiterated the United States’ “ironclad commitment” to Israel’s defense. “The United States maintains an enhanced force posture to defend U.S. personnel, Israel, and partners across the region in the face of threats from Iran and Iran-backed terrorist organizations and is determined to prevent any actor from exploiting tensions or expanding the conflict in the region,” he said.

Washington also cautioned against further hostilities, however, with a senior administration official telling reporters late Friday, after the strikes had begun, that President Joe Biden had encouraged Israeli Prime Minister Benjamin Netanyahu to deter Iran without stoking additional retaliation. “If Iran chooses to respond once again, we will be ready, and there will be consequences for Iran once again,” the official said. “However, we do not want to see that happen. This should be the end of this direct exchange of fire between Israel and Iran.”

Other Western allies expressed similar sentiments. “Efforts were made to avoid civilian casualties. This therefore presents an opportunity to avoid further escalation,” German Chancellor Olaf Scholz wrote on X. “My message to Iran is clear: such massive escalatory responses cannot go on forever. This has to stop now and presents an opportunity for a peaceful development in the Middle East.”

Israel’s strikes on Iran had been anticipated for weeks, with Netanyahu’s government pledging retaliation for an Iranian attack on Oct. 1 that involved nearly 200 missiles fired at Israel. Those strikes, the Iranian government said, were in retaliation for Israel’s assassinations of Hamas leader Ismail Haniyeh in Tehran in July and Hezbollah leader Hassan Nasrallah in Beirut in September. It’s also the second time this year that the two sides have traded missile attacks—following tit-for-tat strikes in April.

“This was a serious escalation—both Israel and Iran have crossed serious red lines,” said Sanam Vakil, the director of the Middle East and North Africa program at Chatham House. “At the same time, Israel has been relatively calibrated,” she added, noting that it avoided attacking Iran’s nuclear facilities or its energy sector.

That calibrated response may provide room for de-escalation in the short term, with Iran’s muted rhetoric so far an indicator that it is unlikely to respond in kind. “I think, at this moment, Iran doesn’t have the interest or the capability to engage in a broader regional war,” Vakil said. “Iran is looking to de-escalate … so that both sides can effectively return to their corners for the time being.”

That doesn’t preclude further hostilities between the two sides, though, and some experts cautioned that Saturday’s assault could be a prelude to further attacks by Israel even if Iran chooses not to retaliate. “The fact that Israel attacked a number of air defense systems on this occasion suggests that maybe they’re trying to lay the ground for a follow-up attack,” said Azriel Bermant, a senior researcher at the Institute of International Relations Prague who focuses on the Middle East. “From Israel’s point of view, this strike has achieved—for now—its objectives. This will not stop Israel from carrying out further attacks, but I think the Biden administration will do everything it possibly can to prevent further Israeli strikes.”

Given the administration’s unbridled support for Israel, the U.S. presidential election on Nov. 5 likely has major implications for Israel’s decision-making, too—both in its decision to strike this week and the possibility of a future assault on Iran.

“Israel had a very narrow window to operate. There was a lot of expectation that Israel would conduct this strike before Nov. 5, with the thinking that the next U.S. president might try to curtail or constrain Israel’s room for maneuver,” Vakil said.

For Israel, a lot will be riding on who prevails between former President Donald Trump and Vice President Kamala Harris. “Netanyahu’s dream is that Donald Trump will become president,” Bermant said. “There’s little doubt that the Netanyahu government would prefer Trump to be president, and it would feel more confident of Israel being able to carry out a more ambitious attack with Trump in the White House.”

Whether a Harris administration would be willing to go further than the Biden administration has to try to curb Israel’s actions in Iran, Gaza, and Lebanon remains an open question. Harris has repeatedly affirmed Israel’s right to defend itself and touted Washington’s “unwavering” support of the country, but she has also been more critical of Israel’s actions at times, at least rhetorically, than Biden has. Her opposition to Iran has been less ambiguous, naming the country when asked about the United States’ “greatest adversary” in an interview with 60 Minutes this month.

“On the issue of Iran, I wouldn’t say both candidates are aligned in terms of tone, but in terms of substance, there is a much more hard-line posture coming from both,” Vakil said. “And this constrains Iran’s room for maneuver.”

At the moment, any further aggression is likely to come from the Israeli side. “I think the Iranians will hold off from retaliating, but I think there will be further escalation later on down the line,” Bermant said. “The question is when it will be, but I fear this isn’t the end of the story.”