Iran’s Deterrence Dilemma
Tehran’s old answers to its problems with America and Israel just don’t work anymore.
Iran cannot deter Israel. Israel’s military and covert capabilities have had free rein to take on the Islamic Republic and its partners. Iran’s deterrence failure has brought the regime to an uncomfortable choice: risk everything to dash for nuclear weapons, or place itself at the mercy of Jerusalem and Washington. How did things get here?
Before April of last year, Iranian deterrence looked solid enough. Tehran had a four-legged stool of answers to Israeli and American threats.
The first leg was the Islamic Revolutionary Guards Corps (IRGC) Aerospace Force’s (AF) arsenal of thousands of ballistic missiles, cruise missiles, and drones, ready to strike around the region. They’d used this tool to retaliate against the U.S. assassination of IRGC Quds Force (QF) commander Qassem Soleimani in 2020, hammer ISIS targets in Syria, and conduct many lower-profile strikes on Kurdish separatists and alleged Israeli safehouses in Iraqi Kurdistan.
The second leg was Iran’s network of proxy groups. The IRGC-QF had strong relations with a robust array of militant groups across the greater Middle East, stretching from recruiting pools among the marginalized Shia populations of Afghanistan and Pakistan, to militiamen in Iraq and Syria, to the Houthis of Yemen. The crown jewel of this network was Hezbollah, the Lebanese militant group that boasted some 150,000 missiles, rockets, and drones able to strike across the length of the land of Israel.
All of these groups were battle-tested, having fought in the Syrian or Yemeni civil wars. The relationship with Hezbollah was especially robust, with talk that the Lebanese group was less a proxy for the Islamic Republic and more a partner with it. Hezbollah appeared to be locked in a mutually assured destruction relationship with Israel, with both sides unwilling to kick off a full-scale war. It was widely assumed that a major Israeli strike on Iran—such as on the nuclear program—would trigger a major Hezbollah strike on Israel.
The third leg of the deterrence stool was terrorism and covert action. Iran’s intelligence services, sometimes in conjunction with Hezbollah, have blown up buildings and gunned down enemies all over the world. For example, Hezbollah answered Israel’s 1992 killing of Hassan Nasrallah’s predecessor, Abbas Musawi, by blowing up Israel’s embassy in Buenos Aires. This leg works through vulnerability—the potential target list against Israel includes not just Israeli diplomatic facilities, but businesses, their assets, and (most despicably) any gathering of Jews regardless of their ties to Israel.
The fourth leg was oil. Iran sits atop the Persian Gulf and the narrow Strait of Hormuz. A fifth of the world’s oil supply (and a fifth of the world’s liquified natural gas trade) passes through the twenty-one-mile-wide Strait. Much of the world’s flexible production capacity sits inside the Gulf’s confines, too. Iran’s naval forces have long prepared to interfere with this trade, and Iran’s missile and air power would also contribute. Iran can do more than interfere with oil tankers, too: getting oil from the ground to the boat is an industrial process with many pipelines and facilities on the way. In 2019, Iran-linked drones hit critical nodes of the Saudi oil network, causing a temporary disruption.
All of this seemed to purchase manageable deterrence for Iran. America, interested more in China and Ukraine than another Middle Eastern war, would not hit Iran directly (save the anomalous killing of Qassem Soleimani, and even that was done outside Iran). America would occasionally use limited force against Iranian proxies in Iraq and Syria, but only if one of the proxies’ many pinpricks drew blood. Iran could pressure America’s dwindling but still ominous presence in its neighborhood, but could back down from direct conflict when needed. America had no hunger for a big fight against Iran’s proxies and certainly not against Iran itself.
Against Israel, the deterrence was partial. Israel had turned Syria into a battlefield, striking Iranian supply lines to Hezbollah hundreds of times in the so-called “War Between the Wars.” Israel’s security agencies thwarted Iranian covert action time and again. Israeli actions inside Iran were bold; they worked well enough to hinder Iran’s nuclear program but not well enough to stop it. But Israel couldn’t overthrow the Islamic Republic. It could fight the proxies, but it couldn’t uproot them. It couldn’t openly strike Iran. It couldn’t bomb the nuclear program due to some combination of Iranian target hardening, Iranian threats, and Israeli fears of angering the United States.
Hezbollah, too, was largely immune inside Lebanon, and analysts spoke with foreboding of the great cost a war with Hezbollah would have for Israel. None of this was comfortable for Tehran, but there was room to maneuver. Indeed, Iran was steadily encroaching on Israel. Iran’s nuclear program had tiptoed to its most advanced position ever. The bomb, in such circumstances, might not be necessary. The strategic and political risks of weaponization outweighed the gains.
2024 wrecked the above status quo. Israeli blows shattered many legs of Iran’s deterrence stool. Just as important, Israel’s willingness to take risks rocketed up. Israel bombed an Iranian consular facility in Damascus, assassinated Hamas’s leader in a Tehran guesthouse, and conducted a string of attacks on Hezbollah’s top ranks, including killing its leader and his likely successor. Three IRGC generals are dead. Taken together, Iran now looks very vulnerable, prompting recent talk of building the bomb.
The IRGC-AF leg of the deterrence stool doesn’t look as good as it once did. Operation True Promise—the April 2024 attack with ballistic missiles, cruise missiles, and drones—did minimal damage. Interception efforts by Israel and its partners took down the vast majority of incoming threats. Israel wasn’t deterred, requiring Operation True Promise 2. This operation used only ballistic missiles, suggesting the drones’ and cruise missiles’ performance wasn’t up to snuff.
The more advanced missiles Iran launched for True Promise 2 did more damage. Even so, the only direct death in either of the attacks was a Palestinian in the West Bank. Since the operation, there has also been reporting that Israel may be running short on interceptor missiles, meaning future IRGC attacks could be more destructive. Still, that didn’t stop Israel from avenging True Promise 2, just as it avenged the original. The Iranian missile threat also didn’t stop the attacks on Hezbollah.
Worse for Iran, the IRGC-AF has seen the need to keep most of its missile force in reserve in both operations. This reflects Iran’s desire to avoid full-scale war and its sense that Israel can win at many levels of escalation. The apparently careful limitation of Iranian targeting similarly suggests a desire to avoid escalation. Iran is trying to muddle through the conflict and its escalations. Israel, on the other hand, is in the driver’s seat.
The proxies, too, have struggled. The Houthis have managed to go toe to toe with the United States for months, but the Houthis are in the outer orbit of Iran’s partners. The Houthi contribution to the fight against Israel has been limited—even their campaign against shipping has a limited ability to drive up Israeli prices. (Indeed, the entire war, Hamas and all, hasn’t broken the Israeli economy.) The Iraqi and Syrian proxy networks haven’t done much to Israel, and had a months-long de facto truce with the United States after limited American pushback. Tehran allegedly imposed that truce.
The real shock of the conflict was Hezbollah. Iran’s most feared proxy tried for a gentleman’s C in the conflict, launching a diversionary campaign in the north but avoiding war. At least that was the plan. After a long battle with Hamas, Israel shifted its energies to the north, sending five divisions over the Lebanese border. Hezbollah’s feared missile and drone force fell short of the society-stopping expectations analysts offered pre-war.
Israel has hammered Hezbollah’s upper echelons, taking initiative again and again with pagers, walkie-talkies, and bunker busters. Hassan Nasrallah came out of the 2006 war a hero of the Arab street. He came out of the 2024 war in a coffin. The Israelis claim they’ve taken the militia down to 30 percent of its original missile and munitions strength. Worse for Iran, supplying Hezbollah will be even harder now that the Assad regime has fallen in Syria.
Hezbollah has had no answer to Israel’s moves. It did manage one impressive strike on one of Benjamin Netanyahu’s residences, yet the Israelis claimed Netanyahu hadn’t stayed there in months. Was this a pulled punch, intended to signal the capability to hit Bibi? Was Hezbollah unable to escalate to war, or merely unwilling? Neither answer can be satisfying for Iran.
The shine has even worn off some of Iran’s covert action capability. Its plots against Israelis abroad are constantly interrupted. Its plots against Americans involved in the killing of Qassem Soleimani have also failed, as have many moves against dissidents abroad. It has had only modest success in inducing criminal networks to act on its behalf, with many plots stopping short of lethality.
This is a far cry from the major terrorist acts and assassinations committed by Iran and its friends in the 1980s and 1990s. Those acts, of course, showed good reasons for Iran not to return to high-profile terror. The attacks caused immediate crises in relations with both the target and the host nation, and the problems linger. The 1994 AMIA bombing in Argentina, for example, put several prominent Iranian officials on the INTERPOL wanted list, where they remain to this day. The bombing’s legacy is constantly coming back up in Iran’s relations with Argentina (a country that enriches uranium!).
Enterprising legislators in the United States have also gotten rid of sovereign immunity for acts of terrorism, enabling private citizens to sue Iran for damages. The resulting judgments have created a new layer of economic sanctions on Iran, one that would be politically costly for U.S. leaders to waive. And, of course, successfully killing former U.S. officials or even President Trump would leave Iran to face America’s focused anger alone—an existential threat to Iran’s regime.
Iran’s old answers to dangers from America and Israel thus don’t work anymore. Hence, there is talk in Tehran of a new answer: the atomic bomb. Will that be enough to solve Iran’s deterrence problem? Come back next week for the surprising answer.
John Allen Gay is executive director of the John Quincy Adams Society, a national network of student groups centered on a vision of foreign policy restraint. He is a former managing editor of the National Interest, where his writing focused on U.S. foreign policy and the Middle East. Follow him on X: @JohnAllenGay.
Image: Saeediex / Shutterstock.com.