Earlier this year, in preparation for a workshop at the Council on Foreign Relations, I developed a set of statistical models to assess the risk of onset of a few forms of political instability–violent rebellion, nonviolent rebellion (link), and coup attempts–and then used those models to generate global forecasts for 2011. Liberia scored in the top five on two of those lists: violent rebellion (a.k.a. civil war) and coup attempts. The models pegged it as having roughly a 15% chance of civil-war onset (3rd highest in the world) and more than a 60% chance of a coup attempt (4th highest) before 2012.

If Liberia is so susceptible to these kinds of political crises, why aren’t they happening now? The country’s horrible 14-year civil war ended in 2003 and has not flared again since then. Elections held in 2005 handed the presidency to Ellen Johnson Sirleaf, and no one has yet tried to depose her by force. For a country supposedly at the leading edge of what Robert Kaplan in 1994 called “the coming anarchy” of state collapse and civil strife (link), that’s a terrific run of political stability.

Of course, Liberia is not out of the woods yet. The year is only half over, and the country is scheduled to hold legislative and executive elections this October. Electoral competition or frustration over its results could trigger civil violence or coup attempts. Fears of exactly that scenario have already prompted more than 20 political parties to sign a Memorandum of Understanding with the Liberian police pledging to conduct their election campaigns with civility (link), but that paper promise is hardly a guarantee against crisis.

Still, let’s take the optimistic view and assume that Liberia crests this hump in its political risk without sliding back into large-scale civil violence or suffering a coup. What explains its ability for nearly a decade now to avoid the “conflict trap” that has plagued so many of the world’s poorest countries after the apparent ends of their civil wars?

Liberia doesn’t get a lot of attention in the U.S. press, but the bits I have seen and heard in the past several years have focused almost exclusively on the figure of President Ellen Johnson Sirleaf. As a plain-talking, Harvard-educated black female economist presiding over a country brutalized by a succession of male warlords, Sirleaf cuts a rare and appealing figure, and foreign governments and international aid organizations seem unusually committed to her government’s success. “We see her as one of us,” U.S. ambassador Linda Thompson-Greenfield told the New York Times. “We don’t want to see her fail.”

I don’t know enough about Liberia to assert anything with confidence, but as a general observer of political instability, my hunch is that international peacekeeping has played a larger role in preserving Liberia’s tenuous stability than the hagiographies of President Sirleaf imply. Since 2003, the United Nations has maintained a large peacekeeping operation (PKO) in Liberia to prevent a return to civil war, support humanitarian work, and train that country’s soldiers and police (link). As of May 2011, that PKO included more than 9,200 uniformed personnel, 1,300 police, nearly 500 international civilian personnel, and roughly 1,000 local staffers and was funded with an annual budget of more than $540 million. That’s a tremendous commitment in a country with a population of about 4 million and a gross domestic product (GDP) of less than $1 billion.

The scale and strength of the peacekeeping efforts in Liberia remind me of the U.N. mission in neighboring Sierra Leone, a neighboring west African country that was also brutalized by civil war and so far has avoided both a resumption of violence and a breakdown of its post-conflict democratic regime. Running from 1999 until 2005, the PKO in Sierra Leone involved as many as 17,000 military personnel at its peak and cost $2.8 billion in total in a country with roughly 5 million residents and a GDP of less than $2 billion (link). At this scale and duration, international peacekeeping operations should stand a better chance of helping domestic rivals overcome the security dilemmas that often drive recurrent conflicts, and Sierra Leone and Liberia’s experiences offer a couple of anecdotes in support of that view. [For excellent academic treatments of civil-war recurrence and settlement, see Barbara Walter and Jack Snyder’s 1999 edited volume and Monica Toft’s 2010 book.]

In short, I believe Liberia’s comparative stability since 2003 is, above all, a testament to the possibility of effective international peacekeeping, especially in smaller countries where intervening forces can more readily achieve a scale that’s virtually impossible to reach in larger countries such as Iraq and Afghanistan. I didn’t have the data required to consider the effects of PKOs in my statistical analysis of violent rebellion and coup attempts and am now eager to try adding them in the future. The 2011 forecasts based on my already-completed analysis could still turn out to be prescient, but I’m certainly hoping they don’t. In the mean time, I would be very interested in hearing from people with expertise on Liberia about their ideas on how that country is beating the odds to stay stable.

UPDATE: Not long after posting these ruminations, I saw a tweet from African Elections (@Africanelection) with a link to an IRIN story, via AlertNet, about Liberia’s current conditions and upcoming election season. The story didn’t change my views about the country’s conflict and coup risks, but it looks like an excellent backgrounder. You can find it here.