The debate over what to do about an Iranian Islamist regime apparently bent on acquiring nuclear weapons has been on or near our front burner for at least six years, and is now almost a settled feature of the policy landscape. There is general agreement in the United States on two points. First, an Iranian nuclear weapons capability is “unacceptable”, as both the Bush and Obama Administrations have put it; and second, we prefer getting to an acceptable outcome without using force. The debate gets testy when we consider that means short of force, such as sanctions and covert technical sabotage, might not work.
It may be too simple to reduce the argument to just two sides—those who fear the regime’s acquisition of nuclear weapons more than the consequences of a war to prevent it, and those who fear the consequences of a war above all else—but in this case simplicity has the virtue of capturing the essence as observers ponder which set of unpalatable risks they would rather run. What is remarkable, though hardly surprising, is that the two sides usually put forth very different assessments of what using force would entail. Those who fear Iranian nukes above all else tend to minimize the risks of using force, while those who fear war tend to exaggerate them. Neither side, however, has persuasively spelled out the reasons for their assessment, leading one to suspect that much of the argument rests on less than rigorous analysis.
What would an honest assessment of the risks of military conflict with Iran look like? How should we think about it? These are difficult questions even for those who are not partisans of one side or the other. Wars are notorious for yielding unintended and unexpected consequences; for reasons explained below, a war against Iran is even harder than usual to bound analytically.
Complexity, Uncertainty and War
Our first consideration in analyzing the likely course of war with Iran is that a U.S.-led attack would be merely the first phase of a war, the opening act of an extended drama whose scenes would unfold, not according to any script, but to an emergent logic of its own. Given the political context in which military engagement would rest, even a minor attack would likely become a major test of strength involving not only the United States and Iran but also a host of allies and associates. It is therefore disingenuous to try to frame military action against Iran as a simple “raid” or even a broader “operation.” We are talking here about war, with attendant potential high costs to all combatants in terms of military casualties, civilian damage and economic disruption.
At least three concepts are key to any coherent discussion of a U.S.-Iranian military engagement: complexity, uncertainty and war itself. By complexity we mean the number of moving parts in a given situation: actors, processes and the connections among them. By uncertainty we mean structural uncertainty—that is, not just ignorance of the magnitudes of agreed casual factors, but the ignorance of the causal factors themselves, and their mutual relations. For example, not only may the U.S. government not know, say, the technical status of the Iranian nuclear program, or the actual state of readiness of Iranian forces. It may not know (or worse, have wrong) the decision-making and implementation protocols of the Iranian government, how the Iranian people and military would react to an attack, what Tehran would ask its allies and proxies to do, and what in fact they will do.
Enemy disinformation, as well as simple error, can also set us on the wrong track. The enemy acts not just on the battlefield but also through an ability to influence our understanding of the situation by means of denial and deception. In this and other ways complexity reinforces uncertainty.1 The large number of actors involved in the Iranian situation would make it very difficult to discern clearly what is happening once the shooting starts, and the scene would remain very fluid as long as the fight persisted, and very likely for a good while afterward.2
As to the meaning of war, it may hardly seem worthwhile to probe something so self-evident, except that it is not self-evident anymore, if it ever was. A simple definition of war is the waging of armed conflict against an enemy, but this is too limited a concept in the 21st century. War in our time involves simultaneous conflict in the military, diplomatic, economic and social domains on four levels: political, strategic, operational and tactical.3 While a war with Iran might begin in the military domain, it would likely expand to others, and while it might begin at the operational or tactical level it would soon encompass strategic and political levels as well.
How these twin expansions would take place has everything to do with context. All wars have one. Would a U.S.-Iran war break out during a protracted diplomatic process, or in the absence or abeyance of one? Would it happen during a period of increasing tension and military readiness, or out of the blue, after one party thinks that the dangers of war have subsided? Would the U.S. government assemble a broad “coalition of the willing”, just a few close allies-in-arms at the ready, or go it alone, even actively dissuading Israel from joining an attack? What would the domestic political situation be in the United States? Would there be an internal political consensus to act, or would there be an active, acrimonious debate? Would the American people be prepared for the aftermath of an initial attack, including rising oil prices and falling stock values? What would the economic situation be like in the United States and beyond? The answers to these questions would have a substantial impact on the war’s course, conduct and outcome.4
Whose War, for What Purpose?
Perhaps the most critical contextual element concerns how senior U.S. decision-makers, the presumed initiators of war in this case, would construe their war aims.5 These aims must somehow affirm that force can be employed to achieve reasonable political and strategic objectives, but those objectives could range from the limited to the expansive. Three sets of objectives come readily to mind.
First, a war could aim to simply delay the Iranian nuclear weapons program through the physical destruction of key facilities and human assets: a Peenemünde option, so to speak.6 Second, war could aim to effectively end the Iranian nuclear program by inflicting broad damage on its components and other key regime assets, military, infrastructure and leadership, combined with the threat to re-strike as necessary: a submission option. Third, war could aim to topple the regime through a concerted campaign against its assets and supporting mechanisms, coupled with support to its presumably less WMD-desirous opponents: a regime change option.
The U.S. government has military options corresponding more or less to these aims. A Peenemünde option would presuppose a narrowly focused, short duration strike largely limited to nuclear facilities. It would aim to inflict serious damage, but also to restrict the scope of conflict. Such an attack would rely on U.S. stealth systems, electronic warfare, cruise missiles and air power. U.S. allies could play a supporting role, especially in dealing with an Iranian response, but American forces would carry the brunt of the action.
A submission option would call for a sustained air and naval campaign against nuclear associated facilities, air defense systems, command centers, offensive missile forces, naval forces and the Army of the Guardians of the Islamic Republic (IRGC), the regime’s praetorian guard and shock troops. This campaign would aim to severely damage the nuclear program, limit Iran’s ability to defend against the attack (and subsequent restrikes, if necessary) and reduce its capabilities for post-attack retaliation.
A regime-change option would require a broad military offensive that could include nuclear facilities, air defenses, Iran’s retaliatory capabilities, leadership targets, regime supporters, and national infrastructure and economic targets. This could include putting some forces on the ground to collect intelligence and neutralize specific targets that are difficult to strike effectively with air power. No large-scale ground operations are likely, but they cannot be ruled out at some levels of conflict and in some scenarios, such as those that posit a need to open and secure passage through the Strait of Hormuz and Persian Gulf.
In general, the more expansive a war’s goals as a plan escalates from strike to campaign to broad offensive, the greater the force needed to achieve those goals, the greater the uncertainty in achieving them, and the greater the consequences of both success and failure. Moreover, a war’s goals at the outset of conflict may not remain stable. Early sudden successes or unanticipated failures can lead to the escalation of initially limited goals, particularly if terminating hostilities proves difficult. Lateral expansion as well as escalation is also possible: Iranian leaders might surrender or agree to a truce but be unable to enforce a similar decision on Hizballah leaders or terror agents around the world. This leads to yet another layer of complexity and uncertainty: Whose war would this be?
A U.S.-Iranian war would probably not be fought by the United States and Iran alone. Each would have partners or allies, both willing and not-so-willing. Pre-conflict commitments, longstanding relationships, the course of operations and other factors would place the United States and Iran at the center of more or less structured coalitions of the marginally willing.
A Western coalition could consist of the United States and most of its traditional allies (but very likely not Turkey, based on the evolution of Turkish politics) in addition to some Persian Gulf states, Jordan and perhaps Egypt, depending on where its revolution takes it. Much would depend on whether U.S. leaders could persuade others to go along, which would mean convincing them that U.S. forces could shield them from Iranian and Iranian-proxy retaliation, or at least substantially weaken its effects.
Coalition warfare would present a number of challenges to the U.S. government. Overall, it would lend legitimacy to the action, but it would also constrict U.S. freedom of action, perhaps by limiting the scope and intensity of military operations. There would thus be tension between the desire for a small coalition of the capable for operational and security purposes and a broader coalition that would include marginally useful allies to maximize legitimacy.
The U.S. administration would probably not welcome Israeli participation. But if Israel were directly attacked by Iran or its allies, Washington would find it difficult to keep Israel out—as it did during the 1991 Gulf War. That would complicate the U.S. ability to manage its coalition, although it would not necessarily break it apart. Iranian diplomacy and information operations would seek to exploit Israeli participation to the fullest.
Iran would have its own coalition. Hizballah in particular could act at Iran’s behest both by attacking Israel directly and by using its asymmetric and irregular warfare capabilities to expand the conflict and complicate the maintenance of the U.S. coalition. The escalation of the Hizballah-Israel conflict could draw in Syria and Hamas; Hamas in particular could feel compelled to respond to an Iranian request for assistance. Some or all of these satellite actors might choose to leave Iran to its fate, especially if initial U.S. strikes seemed devastating to the point of decisive. But their involvement would spread the conflict to the entire eastern Mediterranean and perhaps beyond, complicating both U.S. military operations and coalition diplomacy.
It seems fairly clear then that a conflict with Iran is unlikely to be an isolated event in which the U.S. strikes, Iran retaliates, and it’s over—with Iran either left with a viable nuclear program or not. War is far more likely to be a series of actions played out over time at varying levels of intensity and with a strong potential for escalation. Nor can war with Iran be limited to military action; it will extend to the diplomatic, economic and social domains. U.S. decision-makers might prefer a limited war that would privilege U.S. military and technical advantages, but Iran can force a broader conflict, where it can employ its own political, economic and social means of waging war, including terrorist attacks on U.S. soil and against U.S. interests abroad. The challenge for the United States would be to conduct the conflict so that the longer and broader the war, the more Iran would lose. That objective should affect how the U.S. government would fight in all four domains.
This means that even if the shooting starts at the military tactical or operational levels, the United States or a U.S.-led coalition must plan for all four levels of war and organize itself to ensure unity of command and purpose across those levels. It will, for example, find itself involved in a “secret war” of terrorist attacks and special counterterror operations outside the main theater of conflict. It will find itself in a “political war” involving Iranian and allied diplomatic and information operations to weaken support from other states and actors for the U.S. coalition and mobilize support for Iran. It will find itself in an “economic war” featuring Iranian efforts to disrupt the oil market.7 A “social war” would involve appeals to Islamic solidarity and attempts to weaken popular support for adversary governments through influence operations and attacks aimed at civilians. In such a broad and protracted contest, the United States might not enjoy a favorable balance of advantages. It is by no means clear, either, that the U.S. government is structured to effectively prosecute such a war, or that its intelligence capabilities are oriented properly toward supporting it.
Given these caveats and complexities, it seems to follow that if the United States chose to attack Iran, it would do so in ways that would prevent Iran from expanding the conflict into areas where it held an advantage. The reasoning might go something like this: Since the Iranian regime has many ways to widen a war into domains that do not favor the United States, the best option is to execute regime-change before the regime can open its bag of tricks. Or it might go like this: Start small, but if the Iranians escalate the war, shift immediately to a regime-change option before they can succeed. Almost needless to say, these are hard-to-control and high-risk approaches. A decapitation strategy, we know, did not fare so well in March 2003 against Iraq, and it would probably be harder to pull off against a more deeply institutionalized polity like Iran.
As for a “start small” approach, let’s suppose that the war begins with a limited air and naval operation. Iran could respond in a limited “tit-for-tat” way. But the regime might conclude that the operation is intended to remove it from power (or succeed in doing so unintentionally); if so, it might respond with a high level of violence along several axes of capability. There is simply no way to predict with confidence how radicals in Iran would respond to an initially limited U.S. attack. We must base our predictions largely on what the leadership says, the Iranian regime’s history and our limited intelligence on the regime’s internal dynamics.8 All this is subject to interpretation by experts employing various explicit or implicit models, the most prominent of which casts the regime as a “rational actor” that calculates risks and rewards like any Western state. In this model the highest goal is regime survival, a notion that doesn’t necessarily apply to the Iranian clerical regime. Clerics, even Christian ones from an earlier age, have been known to take their otherworldly prerogatives seriously.
All we can say, then, is that the regime would not try to martyr itself, nor would it be passive. Most likely, Iran would seek to prolong and expand the war, attrite U.S. forces and morale, and weaken the resolve of coalition members. Iran has the means, methods and allies with which to respond in this fashion, and it has made clear that it would use them.9
Important Iranian conventional war assets include short- and medium-range missiles; strike aircraft; missile-equipped naval combatants and small boats; naval mine-laying capabilities; regular army and IRGC special forces; and air defense and coastal defense missiles. These conventional capabilities provide Iran a substantial ability for a local fight in the Strait of Hormuz, the Persian Gulf and along its borders.10 Iran “leans” on the Persian Gulf states from a military and political perspective. Shi‘a populations in Bahrain and Saudi Arabia could be a useful resource and environment for terrorist and irregular operations.
While the Iranian military is at its most dangerous close to its frontiers, we are not “safe” from it anywhere. Missile systems (principally the Shahab 3 variants and Sejjl types) allow Iran to strike targets throughout the Middle East, including population centers, military facilities, infrastructure and U.S. forces based in the region.11 Iranian missile numbers and launchers are limited, but Iran has other means of waging a global conflict, including its allies. For instance, Iran would likely attempt to induce Hizballah to attack Israel. Likewise, Hizballah would expect Iran to assist it and any conflict with Israel. Either case could eventually involve Syria.
Hizballah can now strike targets throughout Israel. Its missiles and rockets are also accurate enough to hit military installations and other important facilities, and it can fire as many as 500–600 per day. Hizballah also has the ability to conduct terrorist or special operations against civilian, military and infrastructure targets outside the immediate theater of war. Sheikh Nasrallah has plausibly threatened to attack shipping in the eastern Mediterranean in the event of a conflict with Israel.12 If Hizballah were to gain access to Syria’s P-800 Yakhont supersonic cruise missile system—a distinct possibility—it could potentially strike targets as distant as 300 kilometers from the Lebanese coast.
Syrian military forces are optimized and deployed for war with Israel, so it would have only a limited ability to directly assist Iran in a conflict with the United States. Syria’s missile systems could target military sites, logistics facilities and airfields in Israel. Syria’s Yakhont coastal defense cruise missile system gives it an enhanced capability to threaten naval and merchant vessels in the eastern Mediterranean.
Hamas is also part of this threat environment, although its offensive and defensive capabilities are much more limited than Hizballah’s. Hamas’s offensive capabilities rest on mortars and rockets of gradually increasing range, bringing more of central and southern Israel under threat with every upgrade. Hamas can now reach central Tel Aviv and beyond Beersheba in southern Israel.
Iran will likely supplement this proxy war by exploiting “images of victory”—such as sinking a U.S. naval unit or displaying U.S. casualties and prisoners to undermine support for the U.S. action and bolster its own supporters.
U.S. conventional military capabilities, especially combined with those of its likely allies, are of course far superior to those of Iran. In many recent years the size of the U.S. defense supplemental alone exceeded the entire Iranian defense budget. But a fight with Iran would not be a fair or clean fight. Winning in any meaningful sense might prove costly.
If Iran’s advantage lies in broadening and widening a conflict once begun, how might we expect its leaders to go about it? At least three types of escalation are open to Tehran: horizontal, vertical and domain.
Horizontal escalation involves the spread of hostilities from beyond the immediate area of conflict to additional geographic areas and political actors.13 Iran’s means and methods, as discussed above, give it the ability to escalate horizontally within the Middle East region and beyond to include Europe and the United States.
Vertical escalation involves the employment of new or increasingly potent weapons systems, attacking new types of targets, or introducing additional types of forces into the conflict.14 What begins as essentially a fight between U.S. and allied air and naval strike assets and Iranian air defense assets could be quickly expanded by Iran to the use of offensive missile systems and naval surface and sub-surface forces in retaliation. Iranian escalation to the employment of WMD (if a war occurred after an Iranian breakout) seems unlikely short of an imminent threat to the regime, but that threat would be hanging in the air as fighting escalated.
Domain escalation refers to the expansion of the conflict from the purely military domain to the diplomatic, economic and social domains, in which Iran has some advantages.
In summary, an attack on Iran could produce dynamics that would push either or both sides to escalate the conflict even if neither had an interest or an initial intention to do so. Iranian civilian casualties, for example, could provoke Iran to step up its response. This becomes more likely as the scale of a U.S. attack increases. Downed U.S. aircrews could lead to search and rescue operations that could become significant military actions in their own right. The need to restrike targets that were missed or inadequately damaged could also prolong the conflict and involve additional forces. As the conflict developed, internal and external political pressures could press both antagonists to escalate the fighting.
On the other hand, there may also be countervailing pressures. A very successful operation could cause Iran to seek a rapid exit, at least from the military aspect of the war. So, too, could increased domestic unrest within Iran. International political pressure brought about by economic disruption of the oil market and fears of military escalation could work to restrain the United States. But we cannot rule out the possibility of escalation, and that knowledge should reinforce the need for clarity of purpose and a full understanding of the risks involved before we pull the trigger.
How It Ends
Just as we cannot rule out escalation, we cannot rule out the harmful protraction of a war. Every war has to end, but how it does so is no simple matter. Even if it were soundly defeated, Iran could complicate the endgame. It’s not simply a matter of our declaring “mission accomplished” and bringing the troops home. As retired Brigadier General Huba Wass de Czege writes:
Although Sun Tzu warned statesmen and generals many centuries ago that long wars benefit no one, they continue to occur, and for some very fundamental human reasons. Statesmen and generals who start wars commit themselves to worthy war aims that are expressed far too specifically—and too soon—in order to get the polity on board. Then they conceive of a strategy based on what they think they know about their capabilities and the situation. They begin taking concrete steps along the path that they think will get them to that end. They learn far too slowly that what they initially thought they knew was in fact wrong or no longer relevant. . . . Things can get much more convoluted by adding allies, different influential actors among the polity, and multiple adversaries. This is why wars are easier to get into than out of.15
Knowing when to end a war relates to war aims and measures of success. A war’s aims should be definitive enough so that success can be measured in some clear way. This is easiest to do where the aims concern discrete things such as the destruction of material targets. Measuring success becomes harder as aims become more political and psychological, such as weakening or toppling a regime, encouraging opposition or deterring further action. Then, too, war aims can expand as fighting escalates or broadens. In a situation in which Iran has retaliated strongly and managed to inflict losses (especially civilian losses) on the United States or its coalition partners, we should expect to hear calls to inflict more damage, to punish the regime and its forces, to bring a “decisive” end to the conflict.
Short of inflicting a total defeat on Iran, an outcome that seems scarcely conceivable, exiting the war could be challenging if Iran chooses to fight on in some form of asymmetric conflict. We might then have to compel Iran to quit, and that could potentially require the application of force well beyond what was originally agreed upon within the United States or with coalition partners. Even then, if the Iranian regime survives at all, it is likely to declare victory, and many of its supporters would believe it. How or when a war with Iran would actually end is therefore no easy topic to nail down. Any attack on Iran of sufficient scale to significantly damage its nuclear program would have rolling consequences both in the short and long term. After the last bomb falls there will be a new reality in the region and beyond.
In the short term, there would be consequences in the military, diplomatic, economic and social domains. The intensity and locus of these consequences would depend on the outcome of the attack and conflict, but there would be “battle damage” in all domains. Short-term consequences would likely include a tense and unstable military situation (unless the conflict ended cleanly) that would require the commitment of forces for monitoring and reacting to emergent threats; and also a potential political crisis in the region propelled by instability and uncertainty about the future, including residual Iranian capabilities to retaliate directly or indirectly.16 The oil market would remain in shock for some time after an attack. Naval mines, wartime damage to facilities and irregular attacks on facilities or tankers would see to that. Social turmoil would be likely as various population groups react to the attack and subsequent conflict. In short, there would be no bright line ending the war in the economic, diplomatic and social realms.
To turn to the long-term consequences, Iran would almost certainly remain a major player in its region. Its adjustment to the war and its outcome would have a major role in shaping regional realities. A beaten, humiliated but still defiant Iran with essentially the same political system and approach to the region and the world would be a long-term, growing danger similar to Iraq after the First Gulf War (or Germany after World War I). This would extend beyond the military to include dangers in the other domains.
The first conclusion we should draw from this exercise is that the U.S. government should be prepared for a long and difficult conflict if it ultimately decides it must attack Iran. An attack might end quickly with few complications if Iran acts “rationally.” We may not like what that means, however: One “rational” ending for the Iranians would be to accept their losses, declare “victory” because the regime survived, lick their wounds, prepare for indirect retaliation, and resume nuclear activities on a clandestine basis. But a war might not end cleanly, and the U.S. administration could find itself in a messy and protracted conflict. This suggests the need for both an expansive approach to net assessment and deep and broad preparation not just of the military but also of the “home front” and the economy, for Iran may choose to fight on these fronts as well as within its own borders and in the region.
How well prepared is the United States for this kind of fight? This is at least in part a question of national or societal resilience. If all options are on the table, as both Bush and Obama Administration spokesmen have insisted, are preparations for employing all options being made ready? If not, then Iran may decide that some of the options on the table lack credibility.
The second conclusion we should take from this discussion is that, in attacking Iran, we would be trading one set of risks for another. Any option we choose, even choosing not to choose, will have political as well as military-strategic consequences. As hard as it is to know the consequences of war, it is just as hard to know the consequences of a decision to “learn to live” with a nuclear-armed Iran. Both courses are fraught and logically open-ended. Thus the fear of potentially negative consequences from a war should not necessarily rule one out. Winston Churchill, reflecting on British policy before World War II, wrote:
If the circumstances are such as to warrant it, force may be used. And if this be so, it should be used under the conditions which are most favourable. There is no merit in putting off a war for a year if, when it comes, it is a far worse war or one much harder to win.17
In any case, if the United States decides to attack Iran it should certainly look before it leaps and prepare itself for a hard landing. Above all, U.S. leaders should not underestimate the scope or misread the broad nature of war and should therefore organize the U.S. government in advance to prosecute it coherently. In light of how we have fared with whole-of-government approaches and unity-of-command issues in Iraq and Afghanistan, this is clearly a requirement we need to take seriously.