What RAND Research Says About Counterinsurgency, Stabilization, and Nation-Building

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RAND has conducted an extensive body of work on what is sometimes characterized as the other war, that is, those conflicts that have mostly engaged the United States over the past 70 years. These "other wars" have acquired multiple descriptive labels to include low intensity conflict, irregular warfare, special warfare, counterinsurgency (COIN), counterterrorism, peace enforcement, and hybrid warfare. These conflicts have often led to peacekeeping, stabilization and reconstruction activities, also characterized as nation-building. Although these terms have distinct and sometimes doctrinal definitions, they generally describe different and often overlapping aspects of continuous military campaigns. For example, the 1992 U.S. intervention in Somalia began as a humanitarian support mission, transitioned to peacekeeping, and then descended into counterinsurgency before being terminated in 1994, only to reemerge as a counterterrorism mission two decades later. The Afghan and Iraq campaigns began as forced regime change followed by stability operations leading to protracted counterinsurgency campaigns during which the ground combat role was gradually transferred to indigenous troops advised, equipped, and enabled by U.S. forces. There is also a large body of RAND literature on terrorism and counterterrorism, mentions of which we included as related to U.S. military interventions.

Since the 1960s, the RAND Corporation has conducted research and analyses on such small wars and on the nation-building activities that typically occur in their aftermath. These studies have varied widely in scope and approach. They have applied both quantitative and qualitative methods. Some studies have focused on specific conflicts, while others have examined broad trends. This introduction succinctly surveys the best examples from this ongoing body of research that are cleared for public release and synthesizes their collective results, focusing on Counterinsurgency, Stabilization, and Nation Building.


Vietnam was the original stimulus for much of RAND's research on counterinsurgency. Two veterans of France's losing struggle against Algerian nationalist insurgents wrote early reports containing insights that would become staples of counterinsurgency literature for decades to come. They argued that the population was the key terrain; that a conventional warfare mindset would handicap population-centric operations, that external sanctuaries needed to be eliminated, and that the causes and motivations of the insurgents had to be understood. RAND researchers also looked at the British counterinsurgency campaigns in Malaya and Kenya and the campaign conducted by the white settler-dominated Rhodesian government. These studies emphasized the importance of unity of command, pointing, in particular, to the British appointment of a single individual with authority over both the military and civil spheres in Malaya.

The war in Vietnam itself became a major research focus. RAND opened an office in Saigon out of which its analysts interviewed defectors and prisoners in an extended study of Viet Cong motivation and morale. This led to further RAND work on the Chieu Hoi program, designed to encourage Viet Cong defection.

Two Vietnam-era reports stand out for their wider implication. One, titled Rebellion and Authority, challenged the hearts and minds approach to securing population support, an approach that remains dominant today. The authors argued that people are moved less by their wishes or aspirations—what they would like to have—than by the alternatives actually available to them. By manipulating these more immediate cost/benefit calculations—establishing rewards and penalties—the counterinsurgent can secure the desired behavior. Coercion, discriminately applied, can thus be an effective instrument in securing the populations cooperation.

Forty years later, RAND employed a different methodology in a similar inquiry. In Victory Has a Thousand Fathers: Sources of Success in Counterinsurgency, RAND researchers matched the results of 30 recently concluded insurgencies against 27 COIN practices, 15 generally considered good (e.g., respecting human rights) and 12 bad (e.g., imposing collective punishments). When tested against the historical record, those COIN campaigns that had a positive balance of good factors versus bad factors were always successful regardless of the distinct nature of the conflict. The authors found that repressive tactics could win phases of COIN operations but generally did not have long-term success. They also found, however, that tangible support and popular support are not always in parallel. In many cases, tangible support appeared to be a more important indicator of success. The population was the center of gravity only when the population was the insurgents' primary source of tangible support.

The second Vietnam-era report of enduring relevance was titled Bureaucracy Does Its Thing. Its author, Robert Komer, had been the principal force behind the creation of the Civil Operations and Local Development Support (CORDS) program. CORDS brought together pacification efforts countrywide in an integrated structure incorporating all U.S. military, State Department, United States Agency for International Development (USAID), and Central Intelligence Agency personnel responsible for supporting local security forces, rooting out Viet Cong cadres and promoting economic development. Komer describes the many obstacles and delays occasioned by bureaucratic resistance encountered in setting up this structure.

A 2006 review of Vietnam-era RAND research, On "Other War": Lessons from Five Decades of RAND Counterinsurgency Research, cited four findings related to counterinsurgency and irregular warfare of particular relevance to the campaigns in Afghanistan and Iraq. These were (1) the importance of civil/military unity of command as exemplified in the CORDS program, (2) the value of amnesty and reward programs for taking enemy fighters off the battlefield on the model of the Chieu Hoi program, (3) the need for border controls to block external sources of support, and (4) the preferability of concentrating stabilization efforts locally rather than concentrating on ambitious nationwide plans.

A few Cold War-era COIN campaigns scored operational successes but most, like that in Vietnam, ended in strategic failure. The lesson drawn by the American body politic and its military leadership from that experience was not to work harder at honing COIN-related skills, but rather to avoid becoming directly involved in such conflicts henceforth. After withdrawing from Vietnam, and for the rest of the Cold War, the United States confined its engagement with insurgencies and counterinsurgencies to advice and material support for one side or the other. There was a corresponding drop-off in counterinsurgency-related studies.

Selected Publications


The collapse of the Soviet Union left the United States as the world's only superpower. Over the following decade, Washington led a series of multinational military interventions, while taking great care to avoid casualties. President Clinton withdrew U.S. forces from Somalia after losing 18 soldiers in a Mogadishu firefight. A RAND examination of public support for U.S. military operations concluded that tolerance for U.S. casualties was based on judgments regarding the benefits and costs as reflected in consensus (or its absence) among political leaders and also the broader support among the public for the mission at hand. When such an agreement is missing or when the stakes of the intervention seem low, as was the case throughout the 1990s, even low costs can erode public support for the intervention. In years following the withdrawal from Somalia, the United States and its allies deployed large and capable stabilization forces to Haiti, Bosnia and Herzegovina, and Kosovo in successful efforts that had relatively low costs in terms of U.S. casualties and that were framed to the public as necessary to prevent humanitarian suffering.

This risk calculus changed dramatically in reaction to al Qaeda's attacks on 9/11. The interventions in Afghanistan and later in Iraq were launched without provisions to counter or deter enduring resistance or to control the costs in terms of American lives or resources. Lessons learned from Cold War-era insurgencies and post-Cold War stability operations alike were ignored. RAND analysis based on historic experience and published as American forces occupied Iraq estimated the manpower requirements for successfully stabilizing a post-conflict society to be on the order of 20 police or soldiers per 1,000 inhabitants. This translated into a force of some 500,000 for Iraq, more than three times the number that was actually deployed there. In other words, these operations were seriously underresourced in ways that undermined their ability to achieve the stated U.S. objectives.

RAND was involved directly and through research in the execution and evaluation of activities in Iraq and Afghanistan. RAND sent several analysts to the Coalition Provisional Authority (CPA) in Iraq to assist in planning coalition operations and strategies for counterinsurgency and institutional development. Following the closure of the CPA, RAND was given access to its archives and began work on a history of the Iraq occupation. This report found preparations for Iraq's post-combat stabilization to have been grossly inadequate. Various agency plans were never fully integrated, not even the several developed within the U.S. Department of Defense (DoD). Most planning tended to be based on unexamined best-case assumptions and largely ignored both recent and more distant experience with post-combat stabilization. The CPA and CJTF-7 (the military command for Iraq) were both severely understaffed throughout their existence. President George W. Bush's decision to delegate responsibility for interagency coordination to the DoD was ineffectual as DoD proved ill-equipped for the task. This left the CPA bereft of adequate guidance, oversight, and support.

RAND also assigned analysts to the U.S. military command in Afghanistan where they helped design and implement the Afghan Local Police (ALP) program. RAND analysts found weaknesses and suggested improvements in COIN campaign assessment techniques, in efforts to build the Afghan army, in programs for encouraging insurgent defections, and in arrangements for civil and military integration.

A review of the Commander's Emergency Response Program (CERP) funds found that this form of spending, usually for small development projects, could be effective when nested within operations. "Softer" outcomes (e.g., building relationships with locals) were more important to implementers than building infrastructure. Almost all operators indicated that implementation was suboptimal and significant changes in the program were desirable. The report recommended that (1) the program be restricted to small dollar-value projects, (2) processes be put in place to ensure that CERP projects were effectively transitioned to incoming units, (3) those units should have personnel with appropriate training and experience to execute CERP, and (4) a more formal role should be established for USAID and civilian authorities in the implementation of CERP.

RAND has also conducted empirical research to assess where and when the United States has undertaken stabilization operations and when it has been successful in achieving its political objectives. Specifically, RAND undertook a review of some 145 U.S. military interventions going back to 1898 when the Spanish-American War resulted in the liberation of Cuba and the conquest of the Philippines. Findings relevant to the counterinsurgency and stabilization aspects of these operation include:

  • The United States has generally been able to achieve its objectives when it applies substantial numbers of forces, particularly ground forces.
  • Pre-intervention planning and nonmilitary resources are critical to success.
  • The ability of the United States to focus on and achieve its political objectives in stability operations appears to diminish as the intensity of conflict increases.
  • The initial quality of host-nation political institutions and the support of the host-nation government can have a substantial effect on the success of stability operations.
  • Third-party interference can substantially affect the likelihood of success.
  • Operations tend to last significantly longer than intended.

Past RAND work has also assessed the effectiveness of U.S. stabilization missions, large and small. RAND drew on several hundred cases to evaluate the efficacy of low-cost and small-footprint military options for intervention in civil conflicts, such as those in Afghanistan, Iraq, Libya, Somalia, Syria, and Yemen. The study concluded that small interventions can reduce the odds of defeat, but not even large interventions can significantly improve the chances of outright victory. Foreign interventions can help prevent the defeat of a partner government, but they do not, on average, increase the chances of a decisive military victory. Thus, interventions of at least 1,000 soldiers roughly double the probability of achieving a negotiated settlement between the government and rebels, and larger interventions can improve these odds still more—albeit at a diminishing rate of return. The same study also concluded that limited strike operations can disrupt militant networks—but generally only when they are conducted intensively and in cooperation with a reasonably effective partner on the ground. Indirect options, such as safe areas, no-fly zones, and interdiction campaigns were found to have limited effects.

Another line of RAND research concluded that successful stabilization depends on success in each of four domains—political, social, security, and economic. Failure in any one of these can doom the entire enterprise. Of course, it is worth noting that there are clearly context-specific factors that shape the success of stabilization (and counterinsurgency) missions. In other words, factors that work in one place might not work in others, even if identically applied.

Selected Publications


In addition to assessing discrete stabilization-related programs, activities, and strategies, RAND launched a series of studies evaluating entire stabilization campaigns from the initial entry, whether forced or permissive, through to their final conclusion. The first volume, America's Role in Nation-Building: From Germany to Iraq, described and assessed six stabilization and reconstruction campaigns, beginning with the occupations of Germany and Japan and moving on to the post-Cold War interventions in Somalia, Haiti, Bosnia and Herzegovina, Kosovo, and Afghanistan. Three subsequent volumes evaluated the performance of the United Nations, the European Union, and the African Union across 18 other interventions.

The first of these volumes evaluated U.S. performance. RAND found that an important determinant of success was the level of effort measured in time, manpower, and money; that the higher the proportion of stabilizing troops to population, the lower the risk of casualties; that unity of command was as important in a peace operation as it is in war; and that it was nearly impossible to put a fragmented nation back together if its neighbors persisted in trying to tear it apart.

Looking across the 24 stabilization campaigns described in these four volumes, RAND found that the majority eventually succeeded in their primary purpose, consolidating an enduring peace, Afghanistan and Iraq being notable exceptions. Most, including Afghanistan and Iraq, also fostered significant economic growth and measurable improvements in governance, democratization, and human development, albeit generally from a very low base.

Interestingly, there did not seem to be any correlation between success or failure to stabilize a society and its prior level of development, experience with democracy, or its degree of ethnic, religious, or linguistic diversity. The two conditions that best distinguished successful from unsuccessful stability operations were whether neighboring governments had been persuaded not to oppose the effort, and whether the contending factions within the society had been coopted into some nonviolent form of power-sharing and peaceful competition.

Selected Publications

By, With, and Through Counterinsurgency

Frustrated with the cost, casualty toll, and duration of the Afghan and Iraqi campaigns, the American public and its leaders again turned away from large-scale counterinsurgency, nation-building, and stability operations. The Obama administration withdrew U.S. forces from Iraq, made no appreciable effort to stabilize post-Qaddafi Libya, and did not intervene to stop Syria's civil war. The emergence of the Islamic State gave rise to an alternative U.S. approach that depended much more heavily on indigenous forces bolstered by U.S. advisers, enablers, and air power. This by, with, and through strategy led to a new emphasis on building partner capacity for COIN and counterterrorism, and to a growing body of research on that topic.

A RAND review of security assistance in Africa found that these programs have had little net impact on political violence there, but significant positive impacts on the quality of African peacekeeping. Researchers found that durable improvements in indigenous security capacity require the U.S. to make long-term commitments, construct a comprehensive political-military strategy, invest in institutions, and maintain a presence to provide advice and assistance over a long-term horizon.

Other findings from this line of research stress the importance of personal relationships and the need to build rapport and assure continuity as U.S. advisers rotate in and out. Material assistance has proved less effective than that focused on training and education. Durable improvements require long term commitment and security assistance might not suffice to save a badly faltering partner given the lengthy timelines involved. In highly fragile states, such programs might also prove insufficient to avoid collapse. And, significantly, RAND found that without stabilization, warfighting often does not provide desired outcomes.


Much of RAND's other war research has helped identify emerging best practices which have since become common practice. Two oft-repeated research conclusions, however, tend to be ignored in practice. The manpower guideline of 20 security personnel per 1,000 inhabitants for pacifying (or, in modern parlance, stabilizing) a society emerging from conflict has been written into U.S. military doctrine but is seldom achieved. The reason is clear. This level of foreign troop density can only be attained when seeking to stabilize fairly small societies, such as Bosnia and Herzegovina (with a population of about 3 million) or Kosovo (2 million). The guideline would have yielded a combined force for the simultaneous operation in Afghanistan and Iraq twice the size of the entire active duty U.S. Army, assuming a combined population of approximately 60 million. Such numbers were actually achieved years later, but only after raising, training, and equipping large indigenous armies.

The importance of unifying the management of the civil and military aspects of both COIN and stability operations is another oft-repeated and generally ignored dictum. The most substantial U.S. effort to do so was the CORDS program instituted in the waning years of the Vietnam War. Komer's account of its difficult and prolonged gestation helps explain why nothing on that scale has been attempted since.

Insurgency is likely to remain the dominant form of armed conflict in the decades to come, as it has been for most of the past 75 years. Today's by, with, and through approach to counterinsurgency has proved a comparatively low cost means to dismantle the Islamic State's caliphate in Syria and Iraq, but similar approaches have not always been successful. Furthermore, almost any successful counterinsurgency effort also requires an extended commitment to reconstruction and stabilization. The United States has often shown an aversion to post-combat stabilization and reconstruction, which tends to threaten the durability of counterinsurgency accomplishments.

Sources of This Research

The studies highlighted and synthesized here were sponsored by the U.S. Army, the U.S. Air Force, and the Office of the Secretary of Defense and conducted in three federally funded research and development centers managed by RAND: RAND Arroyo Center, Project AIR FORCE, and the National Defense Research Institute.

RAND conducted each of the analyses at the request of a senior leader, uniformed or civilian, who faced a major decision and required high-quality, objective research to help inform it. As a result, each analysis was designed to be not only rigorous and reliable, but also responsive, relevant, and immediately useful.

This bibliography is one of a series initiated by RAND Arroyo Center, the Army's federally funded research and development center for studies and analysis.