Israeli leaders on Tuesday were debating how best to respond to Iran’s unprecedented weekend airstrike, officials said, weighing a set of options calibrated to achieve different strategic outcomes: deterring a similar attack in the future, placating their American allies and avoiding all-out war.

Iran’s attack on Israel, an immense barrage that included hundreds of ballistic missiles and exploding drones, changed the unspoken rules in the archrivals’ long-running shadow war. In that conflict, major airstrikes from one country’s territory directly against the other had been avoided.

Given that change in precedent, the calculus by which Israel decides its next move has also changed, said the Israeli officials who requested anonymity to discuss Iran.

“We cannot stand still from this kind of aggression,” Rear Adm. Daniel Hagari, the spokesman for Israel’s military said on Tuesday. Iran, he added, would not get off “scot-free with this aggression.”

As Israel’s war cabinet met to consider a military response, other countries were applying diplomatic pressure to both Israel and Iran in the hopes of de-escalating the conflict.

Almost all of the missiles and drones fired in Iran’s attack early on Sunday were intercepted by Israel and its allies, including the United States and Britain.

The attack, Iran said, was a response to an Israeli airstrike earlier this month, in which several armed forces commanders were killed in an attack in Syria. That attack on an Iranian embassy building in Damascus was so different enough from previous targeted assassinations of individuals in the shadow war that it provided Iran with an opportunity to recalibrate its own red lines.

The strike also destroyed a building that was part of the Iranian embassy complex, normally considered off-limits to attack. Israeli officials said the building was diplomatic in name only, and used as an Iranian military and intelligence base, making it a legitimate target.

Iran, which signaled that it saw the attack as an Israeli break in the norms of the shadow war, felt compelled to retaliate strongly, analysts said, in order to establish deterrence and maintain credibility with its proxies and hard-line supporters.

Israel does not want Iran to conclude that it can now attack Israeli territory in response to an Israeli strike on Iranian interests in a third country, some of the officials said, summarizing the internal Israeli debate. But, they added, Israel also does not want and cannot afford a major conflict with Iran while still fighting a war in Gaza and skirmishing with Iranian proxies along its borders.

The members of Israel’s small but fractious war cabinet, the officials said, are considering options big enough to send a clear message to Iran that such attacks will not go unanswered, but not so big as to spark a major escalation.

The officials described the following options, and their downsides, from which the Israeli leaders are choosing a response:

  • Conduct an aggressive strike on an Iranian target, such as an Islamic Revolutionary Guard Corp base, in a country other than Iran like Syria. (The drawback is that it lacks the symmetry of responding to a direct attack on Israel with a direct attack on Iran.)

  • Strike a mostly symbolic target inside Iran. (Such a move would likely require U.S. consultation and would risk angering the Americans who have advised against such a strike.)

  • Conduct a cyberattack on Iran’s infrastructure. (Doing so could expose Israel’s cyber capabilities prematurely and would not be an in-kind response to a major airstrike.)

  • Accelerate small attacks inside Iran, including targeted assassinations, carried out by the Mossad. (Israel does not claim responsibility for such attacks, so they fail to match the public nature of Iran’s strike.)

Other Israeli options include doing nothing, or adopting a more diplomatic approach, including a boycott of Iran by the United Nations Security Council, other officials said.

At least two members of the cabinet argued at the time of the Iranian attack that Israel should respond immediately, two Israeli officials said, arguing that a rapid response in self-defense would give such a counterstrike obvious legitimacy.

Yet after three days of meetings, the cabinet has yet to decide on a response. On Tuesday, the five-member cabinet met with security officials for two hours of consultations, according to one official, and they were expected to convene again on Wednesday.

The war cabinet discussions are shrouded in secrecy and riven by old rivalries and distrust. Its members share histories of fierce competition as well as personal and political betrayal, which can sometimes color the details that leak out.

According to two officials’ account, the main proponents of immediate retaliation over the weekend were Benny Gantz and Gadi Eisenkot, two former military chiefs and now centrist political allies who crossed parliamentary lines to join the government in the interests of national unity after the Oct. 7 Hamas-led attack on Israel.

But for reasons that remain unclear, no strike took place on Sunday following the Iranian attack.

American officials have publicly and privately tried to persuade Israel that it does not need to retaliate for the Iranian strike. Mr. Netanyahu, they have argued, can “take the win” earned by a successful defense against the Iranian onslaught, which caused minimal damage and injured just one person, a young Bedouin girl.

But American officials have also said they understand that persuading Israel not to retaliate may be impossible. American officials have said they understand Israeli officials believe they must respond to a direct strike from Iran on Israel in a way that the world can see. A covert attack by Israel against Iran, American officials said, would most likely not be enough to satisfy Mr. Netanyahu’s coalition partners or the current Israeli government.

Should that counterattack prompt another round of Iranian missiles and drones, U.S. officials said, American warplanes and naval vessels would once again come to the defense of their ally against their chief adversary in the Middle East.

The United States is also backing diplomatic efforts to pressure and punish Iran, including by imposing tougher sanctions on the country in the coming days, Treasury Secretary Janet L. Yellen said at a news conference in Washington on Tuesday.

Ms. Yellen declined to elaborate on what form the penalties might take, but suggested that the Biden administration was considering ways to further restrict Iranian oil exports. The United States is also looking at ways to cut off Iran’s access to military components that it uses to build weapons such as the drones that it launched toward Israel over the weekend, according to a Treasury official, who declined to be named in order to discuss private deliberations.

“Treasury will not hesitate to work with our allies to use our sanctions authority to continue disrupting the Iranian regime’s malign and destabilizing activity,” Ms. Yellen said ahead of the spring meetings of the International Monetary Fund and the World Bank.

As Israel faces pressure from its allies to avert a broader conflict with Iran, several countries, including Russia, China and Japan, have also been urging Iran to avoid further escalation.

And the European Union is considering expanding economic sanctions against Iran’s weapons program to punish it for last weekend’s attack on Israel and try to prevent any escalation of violence across the Middle East, the E.U.’s top diplomat said on Tuesday.

“I’m not trying to exaggerate when I say that, in the Middle East, we are at the edge of a very deep precipice,” Josep Borrell Fontelles, the E.U. foreign policy chief, said after a hastily called meeting of European diplomats to discuss the crisis.

Reporting was contributed by Eric Schmitt, Alan Rappeport, Cassandra Vinograd, Aaron Boxerman Christopher F. Schuetze and Lara Jakes.

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