How Will Israel Respond to the Iranian Attack?

The answer could determine whether the region is heading for all-out war.

By Daniel Byman, a senior fellow at the Center for Strategic and International Studies and professor at Georgetown University’s School of Foreign Service, and Kenneth M. Pollack, a senior fellow at the American Enterprise Institute. Foreign Policy

The latest Iranian salvo against Israel is raising fears that a regional war will engulf the Middle East. On Saturday, Iran launched a large drone and missile attack against Israel and seized an Israeli-linked container ship in the Strait of Hormuz. These attacks followed the Israeli assassination of several senior Islamic Revolutionary Guard Corps (IRGC) leaders in Syria.

The latest Iranian salvo against Israel is raising fears that a regional war will engulf the Middle East. On Saturday, Iran launched a large drone and missile attack against Israel and seized an Israeli-linked container ship in the Strait of Hormuz. These attacks followed the Israeli assassination of several senior Islamic Revolutionary Guard Corps (IRGC) leaders in Syria.

The Iranian assault on Israel included more than 300 drones, cruise missiles, and ballistic missiles. This is obviously quite a bit more than the 15 ballistic missiles Iran fired at Ayn al-Asad Air Base and Erbil International Airport in retaliation for the U.S. killing of Qassem Suleimani, who led the IRGC’s elite Quds Force, in January 2020. The difference speaks to several points worth considering.

First, the retaliation for Suleimani’s death was about nothing more than restoring Iranian honor. Brazenly killing so important and popular a figure as Suleimani demanded some Iranian response, but Tehran was cautious because it feared an escalatory war with the United States.

Those killed by the Israeli attack on Iran’s Damascus embassy complex on April 1 were not as famous or as powerful as Suleimani, but the retaliation was larger and more sophisticated. The difference suggests that this response was about more than just honor: It was about some element of deterrence.

Iran is well aware of the extent and capability of Israel’s air defenses. The scale of the strike was almost certainly designed to enable at least some of the attacking munitions to penetrate those defenses and cause some degree of damage. Their inability to do so was doubtless a disappointment to Tehran, but the Iranians can probably still console themselves that the attack was frightening for the Israeli people and alarming to their government. Iran probably hopes that it was unpleasant enough to give Israeli leaders pause the next time they consider an operation like the embassy strike.

Nevertheless, while 300 or more attacking munitions certainly sounds like a lot, it also shows signs of restraint that signal Tehran’s own concerns about further escalation. First, Iran could have launched considerably more—not orders of magnitude more but probably at least double what it did without badly depleting stockpiles of its longest-range assets. Second, initial reporting indicates that the attack reportedly focused on one or more military targets, including an Israeli air force base outside Beersheba. That, too, suggests an important degree of caution on Iran’s part. It could have launched at Tel Aviv or Haifa, where any impact would have been far more likely to kill Israeli civilians.

Third, Hezbollah did not participate. Hezbollah is Iran’s ace in the hole. With more than 150,000 rockets and missiles, the Lebanese militant group could overwhelm Israeli air defenses. But Hezbollah is an Iranian ally, not a puppet, and a massive Hezbollah strike could have provoked an all-out war with Israel, something Hezbollah has been trying to avoid. Tehran would only play the Hezbollah card if what it is doing is critically important to it.

All of this reinforces the strategic assessment that Iran is not looking to escalate with Israel and is, in fact, working very hard to avoid escalation. Although Israel has hit Iran’s ally Hamas hard, the war in Gaza has gone very well for Tehran so far. Israel was badly wounded in Hamas’s attack on Oct. 7, 2023, plans for Israeli-Saudi normalization have been put on ice, and much of the Middle East and the wider world is blaming Israel and the United States for all of it. There is no reason for the Iranian leadership to jeopardize all that by giving Israel (or the United States) a justification to do massive damage to Iran, which could snatch defeat from the jaws of their victory.

Moreover, the clerical regime faces significant economic challenges, widespread protests, and violence from ethnic Balochis. In addition, Iran’s military is weak, and it would be on the losing end if there were an all-out confrontation with Israeli military forces, let alone if the United States came to Israel’s aid, as it likely would (and as Iran certainly believes it would). A regional war where Iran might be on the losing end is a risky proposition for a regime already in a difficult position.

Still, Iran has crossed a Rubicon, although it may not recognize it. Iran had never struck Israel directly from its own territory before Saturday. Israel has never openly hit Iranian territory either—all of its attacks on Iran have either been military attacks on Iranians in Syria, Lebanon, and elsewhere or covert attacks on Iranian territory, therefore invoking plausible deniability. This was an acknowledged, indeed trumpeted, military strike on Israel from Iran. It opens the door to Israel now doing the same, and Israel can do far more damage to Iran than Iran can to Israel.

Yet Israel’s calculations are also complex. Iran arms, funds, and trains an array of Israel’s regional foes, including Hamas and Hezbollah. Israeli leaders are preparing for a conflict with Hezbollah, and some even see it as inevitable. Iran also backs the Houthis in Yemen, who are attacking international shipping in the name of striking Israel. Not surprisingly, Israeli leaders believe stopping Iranian influence in the region is perhaps the country’s top priority.

Moreover, Israel has always believed that the sanctity of its deterrent was vital to the survival of the state and the safety of its citizens. Time and again, Israel has responded to any attack guided by the most fundamental logic of deterrence theory: When someone hits you, if you want to make sure they will never do it again, you hit them back 10 times harder. Oct. 7 revived Israel’s commitment to this approach, after years when the country felt safe enough to pull some of its punches to solicit greater international support.

Despite the abject failure of the Iranian attack, Israel might still feel the need to hit Iran somewhere to demonstrate that it will never itself be deterred from responding to restore its deterrent.

The failure of the Iranian attack, however, makes such an Israeli response less likely, and Israel and its military already have their hands full. The war with Hamas is ongoing, and Israel has signaled it intends to clear Rafah despite widespread international resistance, including from Washington. As a result of the war, Israel’s international reputation has plummeted, support has fallen in the United States, and its rapprochement with the Gulf Arab states is on pause. Ordinary Israelis understandably want to return to a more normal life, and the Israeli economy has taken a major hit from both the war and the massive mobilization of reservists. Right now, the Israeli army and most of the Israeli government are looking to shed military problems, not proliferate them.

There are military technical considerations as well. A small but important point is Jordan’s stakes in all of this. The Royal Jordanian Air Force gamely supported Israel not just by shooting down Iranian drones and cruise missiles crossing Jordanian territory but also reportedly opening Jordanian airspace to Israeli fighters to do the same. Although any self-respecting country would have done the former, the latter was exceptional. The Israelis probably won’t forget it—they certainly shouldn’t. Israel should be reticent to launch strikes of its own that violate Jordanian airspace—and the same should be its view toward Saudi airspace for fear of further undermining its desired normalization with Riyadh.

That leaves only a Syria-Iraq or a Turkey-Iraq route for Israeli aircraft and missiles to fly to strike Iranian targets, neither of which is ideal. They are longer legs to many key Iranian targets than the flights across Jordan and Saudi Arabia. Turkey is a NATO ally with some formidable air defenses of its own. There are still Russian air and air defense assets in Syria.

Israel has a quintet of German-made submarines capable of firing cruise missiles of their own. These can be deployed in the Indian Ocean, where their missiles would overfly only international water and Iran itself. But they have only the five, with limited numbers of cruise missiles.

None of that precludes an Israeli counterstrike on Iran, now or in the future, but it certainly complicates it. It suggests that Israel may be more likely to just go back to targeting Iranian personnel and military assets in Syria and Lebanon, and probably Iraq and Yemen, to a greater and greater extent in the future. In other words, Israel won’t be deterred by the Iranian strike, but it probably won’t be provoked by it either.

Finally, the U.S. position is simple. The United States wants to avoid a regional war that could drag in U.S. forces, roil international markets, and complicate the position of Washington’s Arab allies. It wants to protect Israel, but it also wants Israel to wrap up its operations in Gaza. The biggest sighs of relief were probably those in the White House Situation Room overnight, in the belief that neither Israel nor Iran is likely to do much more.

Nevertheless, although both Iran and Israel have strong reasons to de-escalate, politics in both countries are messy, and fear and uncertainty are running high. A simple miscalculation, such as the belief that the enemy will inevitably escalate, could be a self-fulfilling prophecy.

What Saturday’s fireworks hopefully also illustrated is the danger of U.S. disengagement from the Middle East. The region is not better without the United States; it is far more dangerous, unpredictable, explosive, and threatening to America’s own interests. U.S. diplomacy has helped reassure Israel and makes it less likely that Israel will escalate, while U.S. military forces are part of why Tehran hesitated to do more. The latest round of violence shows why it is important for the United States to take the lead on pushing back on Iran and its proxies and bolstering U.S. allies.