When President Barack Obama stepped into the Rose Garden to address the American people on August 31, 2013, his words caught many by surprise. The announcement of the policy decision itself--that President Obama had decided the United States should take military action to punish the Syrian regime of Bashar al-Assad for its use of chemical weapons against its own people--was expected. For more than a year, the administration had warned Assad that using chemical weapons was a red line that, if crossed, would provoke an American response. What took even longtime politicos by surprise, however, was what the president said next:
But having made my decision as Commander-in-Chief based on what I am convinced is our national security interests, I'm also mindful that I'm the President of the world's oldest constitutional democracy. I've long believed that our power is rooted not just in our military might, but in our example as a government of the people, by the people, and for the people. And that's why I've made a second decision: I will seek authorization for the use of force from the American people's representatives in Congress. (1)
For many, this move posed quite a puzzle. At a meeting of his National Security team on August 24, the president by all accounts appeared to have decided to order a limited military strike against the Assad regime to punish it for the August 21 chemical weapons attacks that killed approximately 1,400 Syrian civilians. As late as August 30, Secretary of State John Kerry publicly labeled Assad "a thug and a murderer," leaving little doubt that American military action was imminent (Memmott 2013) However, over the 24 hours preceding the president's Rose Garden address, Obama changed his mind.
A series of developments on both the international and domestic fronts undoubtedly influenced the president's decision calculus. On Wednesday, August 28, talks at the United Nations Security Council on a formal response to the chemical weapons attack broke down in the face of a Russian and Chinese veto of any resolution for military action. The following day, Prime Minister David Cameron shockingly lost a vote in the House of Commons to authorize the use of force. While France continued to stand with the United States, Cameron announced that he would respect the will of Parliament and not join any military action, despite his personal belief that a military response was required (Faiola 2013). Finally, members of Congress were also increasingly demanding a voice in Syrian policy. As of August 29, 140 members, including 21 Democrats, had signed a letter calling on Obama to seek congressional authorization before ordering a military strike; to do otherwise, the letter claimed, would be unconstitutional (Shabad 2013).
The president did not change his mind because he believed a unilateral strike would have been illegal. Indeed, the administration's lawyers formally concluded that "important national interests" in bringing stability to the Middle East and enforcing international norms against the use of chemical weapons justified a unilateral strike, even absent authorization by Congress or the Security Council (Savage 2013). Moreover, in the Rose Garden, President Obama reiterated that he fervently believed the president has the authority to order a military strike absent congressional authorization. Instead, journalistic accounts have argued that Obama's eleventh hour reversal was a response to concerns, both at home and abroad, about the perceived legitimacy of a unilateral strike. Unlike Libya, for which Obama opted not to seek congressional authorization, a strike against Syria would not have the imprimatur of a UN Security Council mandate or, like Kosovo, of a unified North Atlantic Treaty Organization front.
This emphasis on legitimacy is almost certainly correct--but it is also imprecise. Did Obama change his mind out of fear that Congress would exercise its formal powers to block or terminate an illegitimate military action? For all of the reasons detailed by the unilateral powers literature, this is highly unlikely. (2) Similarly, because the United States wields a veto on the Security Council, the president would never face serious international repercussions for a unilateral strike. Perceptions of the legitimacy of a strike could conceivably affect the president's legacy and the judgment of history; however, it is equally if not more likely that Obama's vacillation in the face of Assad's defiant use of weapons of mass destruction against his own people could harm Obama's legacy more than arcane debates over legalistic minutiae had Obama acted, like virtually all of his predecessors, alone and without congressional sanction. Rather, Obama's reversal seems best explained as an effort to avoid the political costs of going it alone in another military strike in the Middle East.
As such, Obama's Syrian gambit reflects a much larger reality in American politics that political scientists often ignore: the contemporary Congress, despite its many institutional failings, still retains considerable influence over the nation's military affairs. To be sure, Congress no longer declares war. Additionally, for a variety of reasons, the appropriations power is a problematic instrument of congressional influence, one so blunt that it has often proved all but impossible to exercise effectively. (3) Similarly, the War Powers Resolution (WPR) has failed to meet the lofty expectations of its drafters who envisioned it as an instrument for congressional reassertion in war powers without having to use the power of the purse to end military actions of which legislators disapproved. Presidents routinely report their actions to be "consistent with" the WPR, even as they refuse to recognize its constitutionality. Furthermore, presidents consistently refuse to report that American forces are deployed into a zone of "hostilities," which would automatically trigger the WPR's 90-day withdrawal clock, even when American forces are routinely taking fire. And Congress, for its part, has time and again proved unable to start the withdrawal clock on its own initiative (Hinckley 1994).
Despite these repeated legislative failures, several recent studies have argued that Congress may retain, in certain conditions, significant influence over the course of American foreign policy through more informal means. For example, Howell and Pevehouse (2007) show that presidents, when deciding whether or not to respond to international crises arising on the world stage, appear to anticipate Congress's reaction. Their findings indicate that the strength of the president's party in Congress is a strong and significant predictor of the probability of a presidential military response.
Moreover, congressional influence persists after American troops are in the field. Recent scholarship finds that presidents backed by strong co-partisan majorities employ larger scale and longer duration military engagements to pursue their foreign policy goals than do presidents besieged by an opposition-controlled Congress on the other end of Pennsylvania Avenue (Clark 2000; Kriner 2010; Wang 1996). And event history analysis of America's most important post-1945 uses of force suggests that a variety of congressional actions--from introducing and voting on legislative vehicles to curtail a use of force (even when they do not pass), to holding investigative hearings, to publicly speaking out against a war or in favor of it--significantly influence the course of American military interventions (Kriner 2010).
President Obama's decision to seek congressional authorization for his proposed Syrian air strikes complements this recent research by plainly suggesting that such authorization is politically quite valuable, even if it is legally of little consequence. (4) Specifically, this article proposes two main mechanisms through which an authorization could pay significant political dividends for the president. First, seeking legislative sanction for the use of force may rally popular support for a military mission in the near term among an ambivalent public. Bolstering the institutional legitimacy of the president's actions may persuade some undecided Americans to back the president's decision. Second, and perhaps even more importantly, authorizations may diminish the intensity with which potential adversaries in Congress later criticize the administration's actions should a military action fail to unfold according to plan. President Obama hinted at this in his September 4 press conference justifying his decision to go to Congress. Without an authorization vote, "Congress will sit on the sidelines, snipe. If it works, the sniping will be a little less; if it doesn't, a little more" (Obama 2013). (5) If forced to make a decision on an authorization, members who vote "aye" may feel their hands tied politically and thus may be significantly less likely to criticize or vote against a military intervention in the future, even if the mission's costs are higher than anticipated.
Ex Ante Influence: An Experimental Approach
Past scholarship suggests at least two ways in which seeking a congressional authorization for military action against Syria could pay political dividends, one ex ante and one ex post. I begin with the first. In the lead-up to the attack, first seeking and then (hopefully) securing congressional authorization could bolster public support for military action amidst an environment of public uncertainty.
Despite Congress's historically low approval ratings, the vast majority of Americans still express a desire for the legislature to authorize the use of force before it commences. For example, an NBC News poll conducted on the eve of President Obama's surprise announcement asked "Do you think that President Obama should or should not be required to receive approval from Congress before taking military action in Syria?" Almost 80% of Americans said...