IN THE AFTERMATH of a chemical attack in the suburbs of Damascus on Aug. 21, President Obama's threat to launch a limited cruise missile strike to "deter and degrade" Syrian President Bashar al-Asad's chemical weapons capability has once again thrust U.S. Syria policy to the forefront of national debate. Though a diplomatic initiative calling on al-Asad to relinquish control of his chemical weapons arsenal and open his stockpile to international inspection may have put plans for any strike on hold, the administration's supporters have insisted that a credible threat of military force is required if a diplomatic solution is to prove workable.

Any delay, however, has failed to reduce widespread opposition to Obama's original plans for a limited strike. Opponents urging the U.S. to sit tight claim the underlying strategic calculus that has guided the administration's approach of limited involvement to date remains unchanged. Others have urged a far more robust response, seeking a sustained application of U.S. military power to alter the fundamental dynamics of Syria's civil war and hasten the end of al-Asad's hold on power.

Underlying this debate are differing conceptions of U.S. interests at stake in Syria's civil war. This Audit aims to clarify the ongoing debate over policy responses by identifying these deeper disagreements over U.S. interests.¹ Its aim is not to resolve these debates, but to make explicit the underlying disagreements that lead analysts and policymakers to their preferred policy positions.

Debating U.S. Interests

Below are six U.S. interests that have been invoked in the public debate over U.S. Syria policy since the outbreak of the war. They appear roughly in decreasing order of the attention given over the course of recent debate. The resulting list does not reflect a deliberate attempt at prioritization. Given the tradeoffs between interests that particular policy responses inevitably entail, consensus over the definition and priority of U.S. interests should be sought prior to debating the appropriate policy response.

1. Upholding an international norm against the use of chemical weapons: A U.S. interest in upholding international norms against the large-scale use and proliferation of chemical weapons has been most forcefully defended by the Obama administration itself, especially in the aftermath of the Aug. 21 chemical attack in the suburbs of Damascus.²

Those who consider the defense of a chemical weapons "taboo" to be a U.S. interest cite a number of salutary effects that they believe follow from its continued maintenance. These include:

a) The deterrence of further large-scale chemical weapons attacks by al-Asad's regime inside Syria, which, if carried out, would likely result in mass civilian casualties by uniquely "heinous" means;³

b) The deterrence of chemical weapons attacks against U.S. allies, partners or assets in the Levant (and beyond) for the remainder of the war;

c) Deterring the development and large-scale use of chemical weapons by other states in the course of future conflicts elsewhere;

d) Deterring the use and proliferation of weapons of mass destruction (WMD) more generally, including nuclear and biological weapons, as well as other outlaw weapons such as landmines; and

e) Decreasing the likelihood of chemical weapons transfer to those who may wish to harm the U.S. or its allies, particularly the Lebanese Shiite militia Hizballah and al-Qaeda linked terrorists who have sought such a capability.

For advocates, then, maintaining a taboo on chemical weapons use is not only rooted in U.S. humanitarian values, but has wide-ranging implications for other U.S. security interests.

Skeptics, however, are quick to point out that al-Asad's regime has already killed tens of thousands of Syrian civilians by conventional means. The type of weapon used for mass killing, they argue, is largely irrelevant. And unlike nuclear or biological weapons, chemical weapons such as sarin must be used in large quantities in order to cause mass casualties. Because the same is true for conventional weapons, they argue, chemical weapons are not in the same class as other weapons of mass destruction.⁴

Critics also point to U.S. passivity in the face of previous use of chemical weapons, particularly by Saddam Hussein in his brutal campaign against the Kurds, as further reason to doubt a U.S. interest in upholding the taboo. Given past inaction, a U.S. strike against Syria now is unlikely to be perceived by others as defense of the taboo, and so any deterrent effect against future development and use of chemical weapons will fail to materialize.⁵ Upholding a norm against the use of chemical weapons, skeptics suggest, should therefore be considered in the context of other potential U.S. interests such as preventing mass atrocity, securing U.S. allies, or preventing international terrorism, if at all.

2. Maintaining U.S. credibility: Although recently bound up in the administration's rationale for limited strikes, a U.S. interest in maintaining credibility has been repeatedly invoked by advocates of greater involvement throughout the debate over U.S. policy in Syria.

Those who view U.S. credibility at stake point to two sets of statements by the Obama administration. The first concerns Obama's call in August 2011 for al-Asad to "step aside" as a result of his failure to lead a democratic transition in Syria. The second concerns Obama's August 2012 statement that al-Asad moving or using large amounts of chemical weapons would cross a "red line," changing Obama's "calculus" on the need for a U.S. response.

These statements have led some to believe that a failure to make good on calls for al-Asad to leave power and forcefully respond to the use of chemical weapons would result in a substantial loss of U.S. credibility with grave consequences for its ability to exercise coercion in general, especially in relation to the U.S. dispute with Iran over its nuclear program. Were al-Asad to go unpunished, the logic goes, Iran would believe the U.S. has been bluffing in its vows to prevent Iran from acquiring nuclear weapons and therefore discount future U.S. threats.

A fear of lost credibility has even been embraced by the Obama administration in its attempts to mobilize public and congressional support for its plans to launch a limited strike. Finally, those concerned with the defense of U.S. credibility point not only to its effect on U.S. adversaries, but to its potential effect on U.S. allies who depend on U.S. assistance for their own defense. Should the U.S. "back down" in Syria, they argue, U.S. allies may be convinced the U.S. "cannot be trusted" and take matters into their own hands. Should they do so, it is implied this would be contrary to U.S. interests.

Other analysts acknowledge the importance of maintaining U.S. credibility for effective deterrence, but suggest that leaders rarely, if ever, assume that the failure of other leaders to make good on past threats is a reliable signal they will be irresolute in the future. Credibility, they argue, is not the product of a reputation for carrying out past threats. Rather, calculations of an opponent's credibility rely on an appraisal of his capabilities and interests over the issue at stake in the here-and-now. A U.S. capability to destroy Iran's nuclear facilities and its interests in nuclear nonproliferation will be far more relevant in Iranian calculations of U.S. credibility, they argue, than anything the U.S. does in Syria.⁷

3. Preventing international terrorism: Outgoing Deputy Director of the CIA Michael Morell made headlines in August when he suggested that the terror threat emanating from Syria made it today's greatest threat to U.S. national security. Those who see this interest threatened by events in Syria point to a number of troubling scenarios:

a) Following a Syrian government collapse, Syria becomes a "safe haven" for international terrorists allied with al-Qaeda, resembling Yemen today or Afghanistan prior to the U.S. war to oust the Taliban.8 Some see this haven developing even while al-Asad retains his hold on power;

b) Foreign fighters flocking to Syria, now numbering more than 6,000 according to US counterterrorism officials, gain technical expertise fighting al-Asad's regime, become indoctrinated with the ideology of violent jihad, and take their experiences back home to launch terror attacks against U.S. interests elsewhere;⁹

c) Jihadists acquire chemical weapons from al-Asad's vast stores as the result of a successful raid today or in the aftermath of government collapse tomorrow and use them against the U.S. or its allies. Some believe that al-Asad's use of chemical weapons today makes them particularly vulnerable to theft because they are more easily seized when transported; and

d) As a result of foreign sponsors supplying the Syrian opposition with arms, terrorists come to acquire weaponry such as advanced shoulder-launched surface-to-air missile systems, creating new threats to civilian targets such as passenger jets.

It is rarely suggested that the U.S. does not have a direct interest in mitigating the risk of international terrorism stemming from the continuation of Syria's civil war. Instead, debate has focused on whether this interest is advanced by the downfall of al-Asad and whether particular responses will ultimately serve to increase or decrease the terror threat specifically directed against the U.S.

Skeptics of greater U.S. involvement believe that efforts to topple al-Asad by whatever means will only empower radical elements of the Syrian opposition, increasing the likelihood that Syria becomes a terrorist safe haven or terrorists come to acquire chemical weapons.¹⁰ Even if U.S. efforts to empower moderate elements of the opposition were ultimately successful in helping them to defeat al-Asad's regime on the battlefield, any transition period would be particularly dangerous in terms of the security of Syria's chemical weapons stockpile. And given the presumed weakness of the Syrian opposition vis-à-vis al-Asad, any material support sufficient to tip the scales in their favor would provide elements of the opposition with precisely the weaponry that increases the terror threat against civilians. If the primary interest of the U.S. in Syria is to mitigate the threat of international terrorism, then, skeptics of greater U.S. involvement suggest this may best be served by al-Asad remaining in power—at least for the foreseeable future.¹¹

4. Maintaining regional stability and the security of U.S. allies: Fears of "spillover" from Syria's civil war have been cited in the context of a U.S. interest in preserving regional stability and the security of U.S. allies. Some have even suggested that the continuation of civil war in Syria puts the entire Middle East at risk for a broader, regional war. And beyond the direct threat to the security of U.S. allies such as Turkey, Jordan, and Israel, some have suggested that regional instability might have second-order effects for other U.S. interests, such as threatening the stable flow of Persian Gulf oil out of the region.¹²

Conflict spillover resulting in regional instability might occur by any number of mechanisms, some more dangerous than others. These mechanisms include:

a) Refugee outflows that strain state capacity and alter the fragile demographic balance of receiving states, sparking domestic strife there (said of Jordan and Lebanon);

b) Hot pursuit raids or skirmishes involving Syrian forces and rebels that cross international borders (as has occurred in Turkey and Iraq);

c) Retaliation by Syria for strikes against al-Asad's regime or the transnational militias that support it (as threatened in response to Israeli and U.S. strikes);

d) Further international intervention by Syria's neighbors (including Israeli strikes inside Syria against the transfer of advanced weapons to al-Asad and Hizballah, Hizballah's intervention to prop up al-Asad, and possible Turkish intervention in northern Syria);

e) The movement of fighters across borders, sparking tensions in the sending states over the role of their domestic actors in Syria's conflict (said mainly of Lebanon in relation to Hizballah's role in Syria, but also of Iraq);

f) The radicalization and emboldenment of sectarian communities in neighboring states as a result of battlefield outcomes in Syria, leading to domestic conflict in those neighbors (said mainly of Iraq); and

g) The flow of weapons across borders leading to new domestic conflicts (as has occurred most recently in Mali as a result of weapons let loose by Libya's civil war).

Like the U.S. interest in preventing international terrorism, it is rarely suggested that the U.S. does not have a direct interest in the security and stability of the region and U.S. allies. Rather, skeptics of greater U.S. intervention seem to believe either a) the likelihood of regional instability resulting from the continuation of Syria's civil war is simply not that high;¹³ b) a U.S. military response would increase the probability of conflict spillover by provoking Syrian retaliation against international targets, including efforts by al-Asad to drive ever greater numbers of refugees into his fragile neighbors;¹⁴ or c) non-military means would be most effective to address the spillover threat, such as greater U.S. humanitarian, technical, and logistical assistance to neighbors experiencing the strain of Syrian refugees (primarily Jordan).

5. Preventing mass atrocity and humanitarian disaster: With over 100,000 Syrians killed in the fighting, over 2 million refugees, and another 4.25 million internally displaced—meaning roughly a quarter of the Syrian population of 22.5 million has been forced to leave their homes—there is no doubt that Syria is experiencing a massive, man-made humanitarian disaster.¹⁵ In light of this harsh reality, liberal interventionists have been vocal proponents of a U.S. interest in preventing mass atrocity and humanitarian disaster in Syria.

Advocates offer at least two rationales for a U.S. interest along these lines: 1) allowing such massive bloodshed to occur in Syria is itself an affront to U.S. humanitarian values; and 2) in the absence of a strong international response to the carnage, the emerging norm of a "responsibility to protect" would be further weakened, leaving future predatory regimes undeterred from following in al-Asad's footsteps.

Developed in the aftermath of the humanitarian interventions of the 1990s, the norm of a "responsibility to protect" (R2P) suggests that states are responsible for protecting their own citizens from mass atrocity. Should they fail to do so, R2P suggest that the burden falls on the international community to mobilize a response in their defense. Like the chemical weapons taboo, defense of this norm is believed to have a deterrent effect on future leaders. Thus, responding to al-Asad's brutality is not only about saving Syrians now, as deeply rooted U.S. humanitarian values might require, but about preventing further abuses by others in the future.

The debate over the appropriate role of U.S. humanitarian values in defining U.S. interests is longstanding.16 However, even when acknowledged as constituting U.S. interests, it is generally accepted that humanitarian values are rarely sufficient on their own to generate an energetic U.S. response to uphold them. The U.S. effort to mobilize a military response to Serb ethnic-cleansing in Kosovo in 1999, for example, was believed to stem from a desire to maintain the credibility of the NATO alliance as much as it was an effort to uphold U.S. humanitarian values. Thus, even if skeptics of greater U.S. involvement acknowledge an interest in preventing mass atrocity, they believe the costs of advancing it must be especially low in terms of blood and treasure in order to act. Syria, they claim, does not meet that standard.17

Skepticism surrounding a U.S. interest in furthering the deterrent effects of R2P runs much deeper. To successfully embed the norm, critics argue, the U.S. and the international community would need to embark on a seemingly endless series of military interventions to prevent mass atrocity. Predatory regimes, as seen in Rwanda in 1994 and Sudan from 2003-2006 in its genocidal campaign in Darfur, will continue to doubt the likelihood of international intervention to compel an end to their predation whether or not the U.S. intervenes in Syria today. Preventive diplomacy and other non-military efforts may be useful in further strengthening a norm against mass atrocity, they argue, but U.S.-led military intervention may be unsustainable as the primary vehicle for strengthening R2P over the long term.

6. Weakening U.S. adversaries: Though attracting far less attention in the public debate than other alleged U.S. interests, some have suggested that a U.S. interest in weakening its adversaries, especially Iran and Hizballah, is also worth advancing in Syria.¹⁸

These advocates of greater U.S. involvement suggest that toppling al-Asad presents a unique opportunity to deprive Iran of its only Arab ally. By splitting up the so-called "axis of resistance," they argue, Iran would become more pliable in the midst of U.S. efforts to coerce Iran to curb its nuclear program. At the same time, toppling al-Asad would weaken Hizballah by depriving the militia of its primary conduit for the transfer of arms and other assistance from Iran.

Moreover, a failure to topple al-Asad would result in a dramatic increase in Iran's power and influence throughout the Middle East. Were al-Asad to successfully subdue the opposition and remain in power, they claim, Iran would be viewed as the "victor" in its broader conflict with Israel, the West, and the Sunni Arab regimes of the Persian Gulf. Given the threats Iran and Hizballah pose to the security of the U.S. and its allies (principally Israel), these advocates believe the U.S. has a direct security interest in weakening or preventing the empowerment of Iran and Hizballah.¹⁹

Like terrorism and regional stability, the debate over preventing the empowerment of U.S. adversaries is generally not about whether the U.S. has an abstract interest in doing so. Rather, skeptics of greater U.S. involvement dispute assessments that Syria's civil war represents a consequential increase in the threat posed by Iran and Hizballah and doubt the efficacy of a military response in reducing those threats.

First, skeptics argue, Iran is unlikely to become more pliable in negotiations over its nuclear program as isolated and strategically vulnerable states are more likely to value the protection afforded by a nuclear deterrent.²⁰ Overthrowing al-Asad would only increase Iranian fears of regime change, they suggest, thereby increasing the value of nuclear weapons. Second, a prolonged US intervention in Syria would also distract the U.S. from dealing with Iran's nuclear program and reduce its resolve for further military action, thereby decreasing the credibility of U.S. threats to act forcefully against Iran should negotiations fail. Finally, attacking Syria would only empower Iranian hard liners hostile to negotiations who would perceive a U.S. war in Syria as a national security crisis for Iran. If weakening U.S. adversaries was determined to be the preeminent interest in Syria, a strategy aimed at prolonging stalemate, thereby draining Iran of blood and treasure, may be the most effective policy response.²¹

Reframing the Debate: Moving from Interests to Policy

Though the debate over U.S. Syria policy is sometimes portrayed as one over whether the U.S. has any interests at stake in Syria at all, the debate should be reframed. The question is not whether the U.S. has any interests in Syria, for even "vital" U.S. security interests such as preventing international terrorism may be jeopardized by its ongoing civil war.

Upon agreeing on the definition of U.S. interests, debate, instead, should focus on four distinct questions: 1) how U.S. interests should be prioritized; 2) the threats Syria's civil war represents to them; 3) what costs the U.S. is willing to pay to secure them; and 4) which strategic objectives and policy prescriptions will best advance them. Doing so will ensure that a robust debate over U.S. policy is based not on implicit assumptions, but rather explicit disagreements on how U.S. interests are prioritized, threatened, and best advanced in the midst of Syria's civil war.

Footnotes

1 "Interest" is a notoriously slippery concept in debates over U.S. foreign policy. For an early discussion, see Arnold Wolfers, "'National Security' as an Ambiguous Symbol," Political Science Quarterly 67, no. 4 (1952), pp. 481-502. For the purpose of this Audit, I adopt a broad view of U.S. interests, encompassing security interests, economic interests, and humanitarian interests.
2 The defense of this interest has also found strong support in the arms control community. See, for example, Oliver Meier, "Syria: A Defining Moment for Chemical Weapons?" Bulletin of the Atomic Scientists, August 30, 2013
3 For a rationale behind the taboo highlighting the indiscriminate and uniquely gruesome aspects of chemical weapons, see Samantha Power's comments before the Center for American Progress on Sept. 6, 2013.
4 See, for example, Allison MacFarlane, "All Weapons of Mass Destruction Are Not Equal," Audit of the Conventional Wisdom, MIT Center for International Studies, July 200; Stephen M. Walt, "Does it matter if Assad used sarin?" Foreign Policy, April 26, 2013; and John Mueller, "Erase the Red Line: Why We Shouldn't Care About Syria's Chemical Weapons," Foreign Affairs, April 30, 2013.
5 See, for example, Richard Price, "No Strike, No Problem: The Right Way to Nurture a Norm," Foreign Affairs, September 5, 2013; and Dov Zakheim,"Don't Attack Syria," National Interest, August 29, 2013.
6 See, for example, Rep. Eric Cantor, "Cantor: America has a compelling national security interest," Richmond Times-Dispatch, September 6, 2013.
7 Jonathan Mercer, "Bad Reputation: The Folly of Going to War for 'Credibility," Foreign Affairs, August 28, 2013, ; and Daryl G. Press and Jennifer Lind, "Red lines and red herrings," Foreign Policy, May 6, 2013.
8 This haven may occur as a result of state failure in Syria due to ongoing conflict for control of the state after al-Asad's fall or as a result of the direct control of the state by extremists sympathetic to al-Qaeda or its cause.
9 Anne Barnard and Eric Schmitt, "As Foreign Fighters Flood Syria, Fears of a New Extremist Haven," New York Times, August 8, 2013. For a useful analysis of this problem, see Seth Jones, "Syria's Growing Jihad," Survival 55, no. 4 (2013), pp. 53-72.
10 Underlying this debate are differing estimates of the size of the extremist element among the opposition. See Charles Lister, "Syria's insurgency beyond Good Guys and Bad Guys," Foreign Policy, September 9, 2013.
11 This conclusion is rarely stated publicly. For one example along these lines, see Edward N. Luttwak, "In Syria, America Loses if Either Side Wins," New York Times, August 24, 2013.
12 Zbigniew Brzezinski, "The steps that Obama must now take on Syria," Financial Times, August 27, 2013.
13 Indeed, recent research by MIT Ph.D. Nathan Black suggests that civil war "contagion" is a relatively rare phenomenon. Cases where it does occur can be traced to specific state policies, such as the expulsion of armed groups across borders or deliberate attempts by states experiencing civil conflict to meddle in the domestic conflicts of others. See Nathan W. Black, "The Spread of Violent Civil Conflict: Rare, State-Driven, and Preventable," (PhD diss., Massachusetts Institute of Technology, 2012).
14 This tool proved one of Milosevic's primarily means to retaliate against NATO intervention in Kosovo, leading to the expulsion of the vast majority of Kosovar Albanians during NATO's 78-day bombing campaign. For the most comprehensive study of coercive uses of forced migration, see Kelly M. Greenhill, Weapons of Mass Migration: Forced Displacement, Coercion, and Foreign Policy (Ithaca, NY: Cornell University Press, 2010).
15 These numbers may in fact understate the true scale of the disaster, given refugees and those internally displaced that have gone unaccounted for in official statistics.
16 For a useful discussion, see Joseph S. Nye, Jr., "Redefining the National Interest," Foreign Affairs 78, no. 4 (1999), pp. 22-35.
17 For an illustrative effort to develop a standard for humanitarian intervention balancing U.S. humanitarian values with the costs of intervention, see Robert A. Pape, "When Duty Calls: A Pragmatic Standard of Humanitarian Intervention," International Security 37, no. 1 (Summer 2012), pp. 41-80.
18 "Weakening adversaries" is presumably a means to protect some other threatened U.S. interests, such as the security of U.S. allies and assets in the region. It is used as shorthand here for any and all U.S. interests threatened by Iran and Hizballah.
19 See, for example, Anthony H. Cordesman, "Syria's ripple effect," Washington Post, July 18, 2013.
20 Examples include Israel, North Korea, and Pakistan.
21 See, for example, Luttwak, "In Syria, America Loses if Either Side Wins."

Brian Haggerty is a PhD candidate in international relations and an affiliate of the MIT Security Studies Program. His research focuses on US foreign policy, Middle East security, and religion and violence.