Iran tells region ‘strong and complex’ attack coming on Israel

Amid U.S. warnings against a counterattack on Israel, Iran is sending a defiant diplomatic message: It is planning a complex response involving even more powerful warheads and other weapons, said Iranian and Arab officials briefed on the plans.

It remains to be seen whether the Iranian threats are real or just tough talk. Israel’s punishing airstrike against Iran on Oct. 26 shredded the country’s strategic air defenses, leaving it badly exposed and sharply raising the risks to Iran if it follows through.

How the Israeli response plays out will depend on the size, nature and effectiveness of Tehran’s threatened strike. So far, Israel has refrained from hitting Iran’s oil and nuclear facilities, essential to its economy and its security, but that calculus could change, Israeli officials have said.

Iran has told Arab diplomats that its conventional army would be involved because it had lost four soldiers and a civilian in Israel’s attack, the Iranian and Arab officials said. Involving its regular army doesn’t mean its troops would be deployed but that the paramilitary Islamic Revolutionary Guard Corps that normally deals with Israeli security matters wouldn’t act alone in this case.

An Egyptian official said Iran warned privately of a “strong and complex” response.

“Our military lost people, so they need to respond,” said an Iranian official. He said Iran could use Iraqi territory for part of the operation and would likely target Israeli military facilities “but much more aggressively than last time.”

Iran isn’t planning to limit its response to missiles and drones, as two previous attacks did, and any missiles used would have more powerful warheads, the Iranian and Arab officials said. Iran said it mostly fired four different types of medium-range ballistic missiles in its last attack on Israel on Oct. 1—Emad and Ghadr missiles and two of Iran’s newest and most advanced, Kheibar Shekan and Fattah.

Another factor in Iran’s response is the U.S. election, the Iranian official said. Iran doesn’t want to influence the U.S. election with its attack, the official said, adding the response would come after Tuesday’s voting but before a new president is inaugurated in January. Iran prefers Kamala Harris over Donald Trump, according to U.S. intelligence agencies.

Officials from Egypt, Bahrain and Oman said Iranian diplomats gave those broad outlines of the response after warnings from the U.S., both public and private, against engaging in a tit-for-tat with Israel.

Linda Thomas-Greenfield, the U.S. ambassador to the United Nations, said last week there would be “severe consequences” if Iran attacked Israel or the U.S.

“We believe this should be the end of the direct exchange of fire between Israel and Iran,” she said.

Following Israel’s attack, Iranian officials initially told other countries in the region that it didn’t intend to respond. Within days, the tone shifted.

On Friday, a top Iranian general threatened “an unimaginable response,” and the country’s supreme leader, Ayatollah Ali Khamenei, weighed in Saturday to warn of a “tooth-breaking response.”

Western officials say they believe Iranian decision makers are debating how and whether Iran should respond, including whether an attack should come directly or from proxies outside Iran to offer a layer of deniability. Israeli officials also believe Iran is seriously considering a response and have warned they are willing to mount a far more aggressive attack in return.

Last week, Israeli Prime Minister Benjamin Netanyahu said the Israeli military had struck Iran’s “soft underbelly” and dismissed “haughty words” from Tehran’s leaders. “Today, Israel has greater freedom of action than ever before,” Netanyahu said. “We can go anywhere that we need to in Iran.”

The U.S. worked to limit Israel’s Oct. 26 attack to military targets, leaving Iran’s nuclear and oil facilities alone. The Arab officials said they were worried Israel wouldn’t be restrained this time, and Netanyahu reiterated last week that preventing Iran from obtaining nuclear weapons remains Israel’s “supreme objective.” Iran denies it is working to build a nuclear weapon.

Israel signaled it could hit these types of targets in its Oct. 26 attack. It struck a facility Iran had in the past used for nuclear weapons work. Satellite imagery showed Israel also hit a very low value target at Iran’s Abadan refinery, experts said.

On Sunday, Iranian President Masoud Pezeshkian said his country can’t let Israel’s attack go unanswered. However, in a sign that Iran is still debating how to retaliate, he said “the type and intensity of our response” could change if there were a cease-fire in Gaza and Lebanon.

The U.S. said its military wasn’t involved in Israel’s most recent attack on Iran, but any retaliation would likely involve American forces helping defend Israel. U.S. Defense Secretary Lloyd Austin has ordered several B-52 Stratofortress bomber aircraft, tanker aircraft and Navy destroyers to the Middle East, the Pentagon said Friday.

The additional military assets will arrive as the USS Abraham Lincoln carrier strike group is expected to leave the region. The U.S. will be without a carrier and its accompanying ships in the region for the first time since shortly after Hamas attacked Israel in October 2023.

Dov Lieber, Laurence Norman and Aresu Eqbali contributed to this article.

Write to Summer Said at Summer.Said@wsj.com and Benoit Faucon at Benoit.Faucon@wsj.com.