How Do We Know an Intervention Has Succeeded?

Syria SIRIA_(f)_0228_-_Guerra_Ribelli_bombardamenti

We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized. That would change my calculus. That would change my equation. . . . We’re monitoring that situation very carefully. We have put together a range of contingency plans. – President Obama

Back in late August of 2012, President Obama uttered words these in an impromptu press conference. At the time, it represented the most concrete and coherent statement of policy regarding the conflict in Syria. With the latest revelation that the Assad regime used chemical weapons on a small scale, calls for intervention in Syria are becoming increasingly vociferous and detractors of the administration are accusing the President of backtracking.

The debate regarding intervention in Syria is a microcosm of the larger debate regarding intervention in general. Those most vehemently opposed to intervention in Syria consistently point to the inchoate metrics that would define success or failure. Indeed, the question regarding intervention in Syria applies to the larger study of the success and failure of past interventions and how that success or failure is defined.

Traditionally, evaluations or metrics for judging humanitarian interventions have relied on four perspectives: 1) human centric; 2) target centric; 3) US strategy centric; and 4) International system centric. These four perspectives do not fully serve as adequate guideposts for judging the success or failure of an intervention—particularly a humanitarian intervention. A synthesis of these perspectives, with a particular emphasis on the human centric, more granular perspective, will provide a more useful set of metrics for evaluating intervention. My framework has six important criteria: 1) saving lives; 2) reasonable prospect of success; 3) right authority; 4) national interest; 5) systemic effects and 6) the political outcome.

Ultimately, the four existing approaches to evaluating intervention fall short. Each of these approaches offers useful but incomplete metrics. I will briefly outline existing approaches and critique their shortcomings. My approach, which I discuss in the section following my critiques of existing approaches, offers a more comprehensive set of metrics. In order to test this approach, I will apply my framework to the interventions in Somalia and the 2003 intervention in Iraq. Finally, I will use my framework to assess the potential outcomes of a military intervention to prevent Iran from acquiring nuclear weapons.

An Assessment of Prior Success Metrics

The four dominant approaches to intervention are useful but incomplete metrics for evaluating intervention. Each approach is briefly discussed below:

Human Centric

Ultimately, the human-centric approach to evaluating intervention is the closest we have to a useful metric. However, the approach comes up short in several key areas. Taylor Seybolt, a professor of international affairs at the University of Pittsburgh, defines this approach in parsimonious, yet useful terms. “If in a humanitarian crisis some people would have died without assistance, but did not die because of the actions of military personnel, the intervention succeeded,” Seybolt argues. “Saving lives is a simple, clear, non-exclusive concept that is often used by policymakers and journalists as a justification for intervention and a measure of its impact.”[1] Seybolt devises his own technique for counting how many lives are saved during a humanitarian intervention.[2] Detractors note that this methodology is not without its flaws. However, this is a simple, quantifiable, lowest common denominator metric for determining the success, particularly of humanitarian interventions.

The human-centric approach, represented here by Seybolt, relies on the key just war principle that “humanitarian military intervention can be justified as a policy option only if decision makers can be reasonably sure that intervention will do more good than harm.”[3] While this is a critical starting point, the approach leaves several things to be desired. Despite Seybolt’s claims to the contrary, this approach does not take into account the aftermath of an intervention. Scholars are increasingly considering jus post bellum (justice after war) as an important component of examining intervention. If an intervention saved lives immediately, then it surely served a valuable short-term purpose. However, it could simply set the stage for a larger conflagration that leads to more loss of life. The human centric approach pays scant attention to the long-term political considerations.

Target Centric

Perhaps the most reductive and flawed approach, a target centric assessment asks simply “Did we kill or capture our man?”  This is sort of like the Zero Dark Thirty approach to intervention, except for the waterboarding, extraordinary rendition, and all that clandestine jazz. It’s the Outkast approach to intervention: just drop them “bombs over Baghdad” until Saddam’s dead. Perhaps the best and most tragic example of this approach was highlighted in May 1, 2003 during President Bush’s “Mission Accomplished” speech. Those who advocate for this approach would have also seen the recent NATO-led mission in Libya as a success. Simply killing or capturing a particular target (such as Saddam Hussein or Muammar Qaddafi) or coercing an aggressor state, whether is it is harming its own population or another state’s, only provides one small piece of the puzzle. This approach would have viewed the first invasion of Iraq as a failure for not getting Saddam. It wholly ignores the political, economic, systemic, and humanitarian consequences of intervention. To be sure, all of these issues must be part of any effort to evaluate military intervention.

U.S. Centric

“The purpose of foreign policy is not to cultivate good relations with other countries under any circumstances. It is rather, to maintain the best possible relations, consistent with the nation’s interests,”[4] notes Michael Mandelbaum, a noted Realist and long time foreign policy analyst, in his critique of Clinton-era interventionism as “social work.” This approach is consistent with Realist principles that view the world through a “self-help” prism. In short, interventions are successful when they serve the national interest and a failure when they do not. This view is critical of the Wilsonian notion that “the United States is exercising power legitimately only when it is doing so on behalf of someone or something else.”[5] While this U.S. centric approach claims to properly grapple with the cold realities of an anarchic international system, it is far too simple in its claims. To be sure, intervening states must consider their national interest. As Seybolt notes, “humanitarian intervention is most likely to succeed when the political interests of the intervening states are strongly engaged.”[6] Yet, this view chiefly ignores the human element. Moreover, it ignores conflicts that may not directly affect the United States, yet certainly require some sort of intervention. Rwanda remains a sobering example.

Systemic Centric

Finally, a systemic approach looks at the effects of an intervention on the overall balance of power in the international arena. This view, propagated by prominent NeoRealists like Kenneth Waltz, is ultimately concerned with the stability of the international system. Perhaps best suited for the Cold War, this approach rings antiquated in an environment circumscribed by the “Global War on Terror.” As a NeoRealist approach, systemic centric approaches view intervention as a tool for the management of international affairs. “To interdict the use of force by the threat or use of force, to oppose force with force, to influence the policies of the states by the threat or use of force: these have been and continue to be the most important means of control in security matters,” Kenneth Waltz argued in 1979.[7] But, NeoRealists would totally ignore the right authority aspect of just war theory, which the modern international legal apparatus sees as vital to enshrining intervention norms. In a world of small scale, localized communal conflict, an approach that privileges the maintenance of power above all else is shortsighted and flawed.

A Syncretic Approach

My syncretic approach to evaluating intervention first takes the human centric approach as primary, but also includes other important elements from each approach. Indeed, interventions should first foremost be engaged in to save lives and any intervention that leads to further loss of life, such as the 2003 invasion of Iraq, should ultimately be deemed a failure. However, to deem an intervention a success, the long-term political trajectory of the country post-intervention, the national interest of the intervening state or coalition of states, and the larger geopolitical, systemic consequences must be taken into account. Moreover, a reasonable prospect of success and right authority ought to be considered. My framework for evaluating intervention is outlined below:

  1. Saving lives: As Seybolt goes to great lengths to demonstrate, the ultimate metric for evaluating success should be how many lives were ultimately saved. This is a difficult and at times intractable task, but it is nonetheless critical. While Seybolt’s methodology is not with its problems, it serves as a useful tool for evaluating intervention, particularly when coupled with the next components of this framework
  2. Reasonable Prospect of Success: This pre-intervention metric provides an important tool for making an initial decision to intervene. I would argue that this fundamental just war concept aids in preventing military interventions that are doomed to fail from the beginning.
  3. Right Authority: Any intervention should have the full support of the pertinent international and regional bodies. Although consensus can be difficult to acquire, particularly in the Security Council, without such a metric strong states will be free to intervene as they see fit.
  4. The National Interest: As Seybolt notes, when states are fundamentally engaged, or have a stake in the game, they are more likely to utilize their full complement of policy options. We cannot deny that the international arena is anarchic and that many states ultimately will act in their own best interests. As such, this is an important component of evaluating any intervention.
  5. Systemic Effects: Along those same lines, it is also important to evaluate the geopolitical effects of an intervention. This may often closely align with the national interest, as I will discuss below in my application of this framework to the 2003 intervention in Iraq.
  6. The Political Outcome: If Clausewitz’s famous dictum that “war is politics by other means” is correct, then this component of my framework is critical, trailing only the saving lives component in importance. While Seybolt and many other liberal internationalists would at the very least try to minimize the importance of this criterion, my framework deems it essential. If an intervention is initially successful, saves lives, and is in the national interest, but ultimately decimates the infrastructure of a country or puts it on a path to further strife as the result of a power vacuum, should we still call it successful?

This framework provides a comprehensive approach to evaluating intervention, considering the decisions to intervene, the success of the mission itself, and the long-term consequences of an intervention. In other words, it takes into account justice of war, justice in war and justice after war considerations. This approach also takes into account all perspectives on success. While some only look at the citizens on the receiving end of an intervention (the human centric approach) or the value of the intervention to the intervener (the US centric approach), this approach values all perspectives.

An Application to Somalia and Iraq

Many of us associate the Somalia intervention with Ridley Scott, Josh Hartnett and the movie Black Hawk Down, which told the story of a U.S. mission to capture Somali warlord Mohamed Farrah Aidid. The movie depicts the frantic and violent story of the U.S. raid in Mogadishu and highlights the perils of intervention.  But the story of the Somali intervention is vastly more complicated.

In 1992, in an effort to provide humanitarian support to the starving people of Somalia, the U.S. led a U.N.-sanctioned effort to provide a stable enclave for humanitarian operations. As factions continued to splinter throughout the country, making the delivery of aid increasingly difficult, the U.S. took the lead through Operation Restore Hope. The operation was largely lauded as a success, in that it helped to produce an environment where the delivery of aid could be safely performed. Indeed, as many as 100,000 lives were estimated to be saved.[8]

The intervention in Somalia was undertaken with the right authority and there was a reasonable chance of success (despite the chaotic factional violence). However, leaving aside a discussion of the dramatic events that came to be known as Black Hawk Down, the long-term consequences of the intervention must surely be deemed a failure according to my framework. First, the political trajectory of Somalia has arguably worsened. It remains a violent, fractured country with hundreds of thousands struggling for food and succor. Second, it did not improve the geopolitical prospects on the horn of Africa. Somalia’s problems continue to spill over into neighboring countries to the present day.

The intervention in Somalia was engaged under the right authority, saved lives, and had a reasonable prospect of success. The story of the 2003 invasion of Iraq is dramatically different. The intervention resulted in the deaths of over 100,000 Iraqi civilians, decimated the infrastructure of the country, harmed U.S. national interest and  the geopolitical configuration of the Middle East by bolstering Iran’s influence, and has set Iraq on a path for continued sectarian strife. Indeed, the reasonable prospect of success is the only criterion the invasion could possibly meet. Unfortunately, those who most vociferously proclaimed that the U.S. would be greeted as liberators and the country would quickly develop into a democracy were surely mistaken. The invasion of Iraq is thus, according to my framework, a catastrophic failure.

Intervening in Iran

Although American and Israeli officials frequently assert that “all options are on the table” regarding Iran, an intervention at this point is highly unlikely. Moreover, the potential for success is even less likely. First, with neither Russia nor China likely to sign on to any Security Council resolution, right authority would be difficult to achieve. Second, although Iran’s acquisition of nuclear weapons could potentially lead to a massive loss of life, an intervention would certainly lead to a large-scale loss of life. A reasonable prospect of success, or lack thereof, is arguably one of the chief reasons that an intervention has not yet taken place. In terms of the national interest, any intervention in Iran would damage America’s standing in a world that has increasingly looked to multilateral, diplomatic mechanisms for solving such problems. Furthermore, it would disrupt the oil market at a time of tenuous financial stability in the United States and across the globe. Systemically, the invasion would likely result in a febrile ratcheting up of violence throughout the region, as Iran’s patrons would seek to punish Israel for the invasion. Lastly, for those interested in a democratic future for the Iranian people, an intervention would be the worst possible enterprise. “Instead of widening Iran’s deep internal fractures,” argues Karim Sadjadpour, an Iran expert at the Carnegie Endowment, “a military strike would help repair them.”[9]  According to my framework, an intervention in Iran has no chance of success.


The very concept of international military intervention is fraught with complicated legal, political, economic, moral and normative issues. Intervention violates the fundamental principle of the Westphalian international system, that is, state sovereignty. But, few would deny that at some times and for some conflicts, military intervention is necessary. When such a case exists, measuring its success or failure requires a long-term and comprehensive approach. Previous efforts at evaluating interventions have typically relied on reductive or myopic approaches. Just war theory provides key concepts that can aid in this approach. As such, my proposed framework provides an approach that is stringent in its requirements for success, but should induce a sense of modesty and circumspection regarding intervention. It also allows for all perspectives to be taken into account when evaluating success or failure. In human affairs, we are all too likely to suspect that we can change events through exertion when at times there is little or nothing that can be done.

[1] Taylor B. Seybolt, Humanitarian Military Intervention: The Conditions for Success and Failure (Oxford: Oxford University Press, 2008), 30.

[2] Ibid., 32.

[3] Ibid., 30.

[4] Michael Mandelbaum, “Foreign Policy as Social Work,” Foreign Affairs, vol. 75 (1996), 31.

[5] Condoleezza Rice, “Promoting the National Interest,” Foreign Affairs, vol. 79 (2000), 47.

[6] Seybolt, Humanitarian Military Intervention: The Conditions for Success and Failure, 20.

[7] Kenneth Waltz, Theory of International Politics, (Long Grove: Waveland Press, 1979), 209.

[8] Walter Clarke and Jeffrey Herbst, “Somalia and the Future of Humanitarian Intervention,” Foreign Affairs, vol. 75 (1996),

[9] Karim Sadjadpour, “Ayatollah for a Day,” Foreign Policy, November 10, 2011,