A mural depicting the former Iranian Supreme Leader Ayatollah Ruhollah Khomeini and the current Iranian Supreme Leader Ayatollah Ali Khamenei in Tehran, Iran, March 2024
A mural depicting the former Iranian Supreme Leader Ayatollah Ruhollah Khomeini and the current Iranian Supreme Leader Ayatollah Ali Khamenei in Tehran, Iran, March 2024
Majid Asgaripour / West Asia News Agency / Reuters

On April 1, Israeli warplanes attacked a building in Damascus that is part of the Iranian embassy there, killing seven senior figures in the Iranian military. Tehran has yet to respond. But when it does, the scale and nature of its actions will help answer a basic question at the heart of many debates about the current situation in the Middle East: Has U.S. deterrence worked against Iran?

Washington has had its difficulties with Iran since the Islamic Republic was founded in 1979, and since then, the United States has struggled to find a successful strategy for dealing with it. Despite the fact that the U.S. economy is more than 16 times as large as Iran’s and its military budget more than 100 times as large, Iran has consistently blocked U.S. efforts to create a stable regional order. Although it is hard to think of any measure in which Tehran is even vaguely competitive with Washington, all U.S. efforts to sideline Iran have failed for most of the last four decades. This presents a puzzle. The disparities between the two sides are so great that it could be supposed that deterring Iran’s malign behavior would be a straightforward question of properly calibrating U.S. policy and resolve. This was the logic behind the Trump administration’s “maximum pressure” campaign from 2018–21, and it has also informed Washington’s course in the Middle East following Hamas’s October 7 attack on Israel. But that assumption is mistaken.

The problem is not with deterrence. Rather, it is that Washington has been trying to do too much with Tehran, with too limited a set of tools, over too long a period of time. Although prioritizing U.S. objectives and adopting a more flexible set of responses will not fix the Middle East, it will certainly improve it. Iran may remain a challenge for U.S. policymakers—but it will at least become a more predictable one.

A SLIPPERY ADVERSARY

For the last 45 years, the United States has tried to deter and compel Iran. But this is the wrong approach. Deterrence theory is not suited to dealing with the sorts of challenges that Tehran presents today. Deterrence was developed during the Cold War, when—from the successful testing of a Soviet atomic bomb in 1949 to the end of the Soviet Union in 1991—U.S. strategists were rightly preoccupied with preventing a global catastrophe. To that end, they labored mightily to persuade the Soviet Union to not abandon the status quo by using nuclear weapons. At heart, Washington’s strategy was a bet that if nuclear war broke out, the conflict would impose massive, unbearable costs on both sides. The hope was that the U.S. nuclear arsenal on land and sea and in the air, combined with a show of resolve, would ensure Soviet inaction. Costly as it was, neither side would then pay the much higher costs of all-out war. “Compellence,” meanwhile, is the effort to persuade an adversary to stop or reverse an action it has already begun. Compellence is much harder than deterrence, as it requires an adversary to stop doing something already in motion, and it requires the compeller to follow through on their specific threats. It is estimated that compellence works only about a third of the time, often because the other side refuses to capitulate.

Neither deterrence nor compellence theory has solved the problem of what to do with Iran. From the Islamic Republic’s founding, the United States has had to decide whether to take Iran’s revolutionary rhetoric literally—and given both its tone and Iran’s support for violent nonstate actors throughout the region, it has often seemed foolish not to. Successive U.S. presidents have accordingly regarded Iran’s efforts to project strength as threatening, and Tehran, in turn, has perceived Washington’s responses as equally so. Each pushed the other toward developing greater capabilities, which each responded to by increasing its military strength in the region. Covert action also increased. Not surprisingly, the United States became preoccupied with the threats coming from Iran, and Iran became preoccupied with the threats coming from the United States.

Iran responded to these challenges by developing a flexible, robust, and dynamic set of tools designed to blunt the effects of U.S. pressure. Conscious that it could not win a conventional war with the United States, Iran invested in developing its own paramilitary organizations and creating, training, and supplying nonstate actors throughout the region. Iran has also built a significant overseas intelligence presence capable of sabotaging local infrastructure and supporting regional opposition movements. Tehran has invested in highly capable missile and drone programs, and its spies have waged cyberwarfare on neighboring countries’ systems. Iran’s nuclear efforts are another weapon in its arsenal, and Tehran accelerates, decelerates, and even occasionally abandons its program in response to changing conditions. These responses are all inherently flexible. Iran is constantly probing which actions elicit which reactions, and it uses ever more creative tactics to do so. In particular, Tehran seeks to make its actions “attributable but deniable,” in the words of a former CIA operations veteran, and accordingly sows just enough confusion to forestall an immediate response from targeted states or their Western allies. But Iran also relies on the diversity and dispersion of its tools to make its adversaries reluctant to respond directly.

Iran’s neighbors are all within range of its missiles. Initially, that engendered indifference to Tehran’s nuclear program. Indeed, more than a decade ago, Kuwait’s foreign minister privately waved off his country’s concern at the prospect of an Iranian nuclear weapon, asking, “If they already have a gun to your head, what does it matter if they point a cannon at your back?” Iran’s neighbors continue to doubt that they can pressure Tehran to behave better. In August 2022, Kuwait and the United Arab Emirates restored diplomatic relations with Iran; they were followed by Saudi Arabia nine months later. Kuwaiti and Emirati officials said privately that they did so because they thought diplomatic ties would create more predictability in their relations with Iran, not because they thought good relations with Iran were possible.

STOP IT!

When seeking to deter Iranian threats, the task for the United States and its allies could not be more different from the task they faced deterring the Soviet Union during the Cold War. Then, the goal was simply to persuade the Soviets to not act in a specific way. The Iranians, by contrast, are acting in an evolving set of ways, both directly and indirectly. Compelling them to stop all their malign actions, in multiple locations, using multiple instruments, is a game of whack-a-mole. The challenge is made even more difficult by Washington’s tendency to project its own assumptions on Iran and assume it understands the Iranian mindset. Events have proved this belief dangerously wrong. U.S. policymakers, for example, have long worked on the assumption that Iran does not want to be sanctioned. Yet many of the most powerful figures in the country and their families—including former Petroleum Minister Rostam Ghasemi and former National Security Adviser Ali Shamkhani—have been accused of being deeply involved with smuggling networks. The profitability of their activities lies precisely in the perpetuation of sanctions. The luxurious villas and sports cars of Lavasan, a city just 30 minutes northeast of Tehran, are a tribute to how well some powerful Iranians are doing under the American sanctions regime. Nor is it correct to assume that Iran fears a limited military confrontation. Iran was indifferent to military casualties in its war with Iraq in the 1980s, continually sending waves of ill-trained troops into battle to draw Iraqi fire and detonate land mines. Although many Iranian leaders came to decide that the tactic was wasteful, Tehran has nonetheless remained willing to risk its soldiers’ lives, even when the country’s strategic interests are not directly at stake. Most recently, Iran has lost hundreds if not thousands of soldiers in Syria, despite their purportedly serving in an advisory role.

The United States is also part of the problem. The complexity and variety of Iranian actions that Washington finds offensive makes it difficult to develop a political consensus in the United States to reduce pressures on Iran. As U.S. rhetoric on Iran seems to become only more confrontational, Tehran’s conviction hardens that U.S. hostility is either constant or increasing—and thus inevitable. The Iranian leadership has, as a consequence, decided that its only option is to invest more heavily in what one Iranian scholar called “Iran’s instruments of deterrence,” seeking to persuade Washington that the costs of direct conflict would be too high to contemplate. The two principal means of doing so are Iran’s missile program and its network of allied militias, the so-called axis of resistance that spans Iraq, Lebanon, Yemen, and the Palestinian territories. The sophistication and utility of Tehran’s arsenal was demonstrated in a series of strikes on Saudi oil facilities in September 2019. Meanwhile, the reach of its proxies has become evident in the aftermath of Hamas’s October 7 attacks, as Houthi assaults on Red Sea shipping squeeze global trade, Hezbollah threatens Israel’s northern border, and proxy groups in Iraq and Syria attack U.S. troops deployed to prevent the return of the Islamic State (or ISIS).

Although the United States has refrained from direct strikes on Iran, some in Congress, including two U.S. Senators, Tom Cotton, Republican of Arkansas, and Lindsay Graham, Republican of South Carolina, argue that any strategy that does not involve military attacks on Iranian soil is doomed to fail. “The only thing the Iranian regime understands is force,” Graham recently declared. “Until they pay a price with their infrastructure and their personnel, the attacks on U.S. troops will continue.” The solution is to “hit Iran now,” he added. “Hit them hard.” This would, at a minimum, risk a broad regional war in which Iran would unleash the full force of its “instruments of deterrence,” seriously threatening U.S. allies and tens of thousands of U.S. troops in the region. It could also require the United States to fight yet another sustained military operation in the Middle East at a time when Washington’s attention is increasingly on the Asia-Pacific. Past administrations have been careful not to cross this line. Even the Trump administration’s January 2020 assassination of the head of Iran’s Quds Force, Qasem Soleimani, took place on Iraqi soil—not in Iran. Although this may have been a consequence of logistics or intelligence, it also shows Washington’s reluctance to operate on Iranian territory.

NO WAR, BUT NO PEACE

Washington’s strategy has had one notable success: it has clearly succeeded in deterring Iran from escalation. Iranian proxies have ended their efforts to target U.S. facilities since a drone linked to pro-Iranian forces killed three U.S. soldiers in northern Jordan on January 28. After the attack, U.S. warplanes struck the facilities of Iranian-backed groups in Iraq and Syria, killing some 45 people. Washington’s capability and willingness to decisively destroy a wide variety of targets persuaded the Iranians to end their attacks on U.S. outposts, at least for now. But the United States has not succeeded in compelling Iran to roll back the use of its asymmetric tools.

This general failure can be attributed to the disparities between the United States and Iran. The United States is a wealthy global power with assets and interests everywhere. It has a keen interest in sustaining global order, which not coincidentally leaves Washington in a commanding global position. The Iranian government, by contrast, has grown accustomed to deprivation and the lack of development, and it has relatively little overseas that it is determined to preserve. Its interest is in subverting the global order, which it does with two things in mind: the knowledge that the U.S. interest in sustaining that order will make the United States act conservatively and within the boundaries of international law, and that Iranian protests against the global order will win sympathy from governments and billions of people who object to it. That is why, since taking office in August 2021, Iranian President Ebrahim Raisi has abandoned rapprochement with the United States and focused instead on attacking the global status quo. To that end, Iran has forged closer ties with China and Russia, which have their own interests in diminishing U.S. hegemony and are happy to quietly abet Iran’s efforts. Time is on Tehran’s side. Iran has learned to adapt to U.S. efforts to isolate it, and its current leadership is strengthened and enriched by most U.S. sanctions.

SMALL WINS ARE STILL WINS

Washington can manage the problem of Iran by using a three-pronged approach. First, the United States should rigorously prioritize its objectives with Iran. Although Washington should not be willing to accept all manner of Iranian misbehavior, Tehran should nonetheless have a clear understanding of what is most important to Washington. Too long a list invites Iranian picking and choosing, and the United States should be the one picking and choosing. Direct attacks on U.S. personnel should remain off-limits, as should the development of nuclear weapons. But the United States should not seek to be the chief opponent of Iran’s myriad illegal international activities, including smuggling and hostilities against neighboring states. Washington should, instead, work to help build the capabilities of friendly states in the region to respond to Iran.

Second, the United States should be less predictable in its responses to Iranian actions. Because Tehran constantly probes U.S. responses, it knows where Washington’s redlines have been drawn and, therefore, precisely where it must stop. A more flexible U.S. approach would help persuade the Iranians that low-level activities can have higher-than-expected costs; this, in turn, would diminish Iranian experimentation and cause the Iranians to use more restraint. The United States needs to develop more ways to threaten Iranian government assets, especially military and intelligence targets. U.S. options should include limited military action and cyberattacks.

Third, the United States needs to recognize that its hand is strengthened when Tehran believes that there is some prospect for greater accommodation with Washington. When Iran’s leaders believe that there is no action they can take to blunt U.S. hostility, it encourages them to misbehave. Furthermore, if punishment is inevitable, then an increase in Iranian hostile activities carries no marginal risk. If Tehran believes that Washington is potentially willing to accommodate it, then it will be incentivized to reduce tensions. The goal should be something closer to détente than rapprochement. The more Tehran believes its conflict with Washington is existential, the more committed it will be to its own tools of deterrence. And the more realistically the United States looks at Iran, the more modest it must be about its ability to foster the collapse of Iran’s government, let alone ensure that one more favorable to U.S. interests emerges. Iran’s government may fall under its own weight, and that may benefit U.S. interests. But regime change in Iran should not be a U.S. government objective. U.S. and British support for the overthrow of Iranian Prime Minister Mohammad Mosaddeq’s government in 1953 is still remembered in Iran as a moment of national humiliation. Even bringing down an unpopular regime is unlikely to make the United States many friends.

Weaker powers such as Iran have an advantage over powers many times their size. Because they have a limited number of adversaries and everything to lose, they are often more highly motivated than their powerful opponents. Yet because they are weaker, they rarely win. An overall win for the United States, which has global interests and myriad other priorities, is also unlikely—meaning that a string of small victories on the most important issues is the right target. Further restricting Iran’s actions and introducing more predictability in the Middle East would be a great improvement. Iran has learned to play the current game well, and it understands its advantages. Although the United States cannot erase all the conditions that favor Iran, it can work to level the battlefield with Iran, advance the security of U.S. partners and allies, and diminish the possibility of a U.S.-Iranian conflict that inflames the entire Middle East.

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  • JON B. ALTERMAN is Senior Vice President and Director of the Middle East Program at the Center for Strategic and International Studies.
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