Peacekeeping Works Better Than You May Think

Does peacekeeping work? Janice Stein (University of Toronto) and I had a lively exchange on this subject on the CBC radio program “The House” this weekend. Have a listen.

In the interview, I said that more than two dozen major peace operations have been deployed over the past 25 years in countries emerging from civil wars, and that although some have been terrible failures (e.g., Rwanda 1994), their overall record has been reasonably good at preventing a recurrence of fighting.

Prof. Stein was unconvinced. Some studies, she said, “show that the majority [of peace operations] are failures and that there is a return to violence after 5 to 7 years. So I think the record is the reverse.”

So, which is it? Does peacekeeping generally help to prevent a return to violence, or does it generally fail to do so?

The answer to this question matters – quite a lot, actually. If peacekeeping is ineffective and if outsiders can do little to help post-conflict societies transition towards a more stable peace, as Prof. Stein suggests, then Western policymakers and other leaders would be foolish to consider contributing to, or even supporting, such efforts. If, on the other hand, peacekeeping has a reasonably positive record, it would seem foolish for the same policymakers not to support these efforts.

Prof. Stein is a fine scholar and fluent analyst of international affairs, but she’s not correct about the peacekeeping record.

Michael Doyle (Columbia University) and Nicholas Sambanis (Yale University) demonstrated in 2000 that the presence of a large peace operation in a country emerging from civil war significantly reduced the chances of that society slipping back into violence. They reached this conclusion by analyzing post-conflict countries that had, and had not, received peace missions, and by holding other factors constant, including the intensity of the preceding war, the type of conflict, etc.

Their finding has been replicated, modified, and reconfirmed many times in the ensuing decade-and-a-half and is now widely accepted among international security scholars. One recent survey of this literature put it simply: “there is considerable evidence that [United Nations peacekeeping operations] are effective in maintaining peace.” In fact, most debates on this subject are now focusing not on whether peacekeeping reduces the risk of renewed fighting, but on how much it does so.

Of course, this does not mean that every peacekeeping mission has succeeded or will succeed; rather, it indicates that “on average” peacekeeping works to reduce the risk of renewed conflict. It is a statistical relationship – and a very strong one, as other contributors to this literature, including Paul Collier (University of Oxford) and Page Fortna (Columbia University), have demonstrated.

This finding may seem counter-intuitive at first, given lingering images of failed peacekeeping efforts in Rwanda and Somalia, for example, but it begins to make sense if you consider how many countries have navigated the war-to-peace transition with the assistance of international peacekeepers – including El Salvador, Nicaragua, Namibia, Mozambique, Sierra Leone, Cambodia, East Timor, Bosnia and Kosovo. Perhaps these cases have fallen from public view precisely because they are no longer at war. “Still no return to massive bloodshed in Bosnia” is very important news to the inhabitants of that country, but don’t count on seeing this headline in tomorrow’s paper. If it doesn’t bleed, it doesn’t lead.

Nevertheless, the evidence is clear: On balance, peacekeeping works reasonably well at preventing conflicts from reigniting. I’ve included a list of studies at the end of this post in case you wish to read further, but I’ll leave the last word to Steven Pinker of Harvard University, who, in the video clip below, sums up the findings of this scholarship more eloquently than I can.

In response to the question of whether peacekeeping works, Pinker says:

The answer from the statistical studies is: absolutely, they work massively. A country is much less likely to fall back in civil war if they’ve got armed peacekeepers. And the better financed and armed the peacekeeping force, the more effective they are…

The United Nations does a number of things badly, but it does a number of things well, and one of them is peacekeeping – on average, not 100 percent of the time. The headlines would never tell you that. Only a statistical study would.

Further reading:

  • Anke Hoeffler, “Can International Interventions Secure the Peace?” 2014. Area Studies Review 17(1):75-94.
  • Collier, Paul, Anke Hoeffler and Mans Soderbom. 2008. “Post-Conflict Risks.” Journal of Peace Research 45(4):461-478.
  • Doyle, Michael W. and Nicholas Sambanis. 2000. “International Peacebuilding: A Theoretical and Quantitative Analysis.” American Political Science Review 94(4):779-801.
  • Doyle, Michael W. and Nicholas Sambanis. 2006. Making War & Building Peace: United Nations Peace Operations. Princeton: Princeton University Press.
  • Fortna, Virginia Page. 2008. Does Peacekeeping Work?: Shaping Belligerents’ Choices After Civil War. Princeton: Princeton University Press.
  • Gilligan, Michael J and Ernest J Sergenti. 2008. “Do UN Interventions Cause Peace? Using Matching to Improve Causal Inference.” Quarterly Journal of Political Science 3:89-122.
  • Havard Hegre, Lisa Hultman and Havard Mokleiv Nygard, “Evaluating the conflict-reducing effect of UN peace-keeping operations,” Paper prepared for the European Political Science Association Convention, Berlin, 21–23 June 2012.
  • Sambanis, Nicholas. 2008. “Short-Term and Long-Term Effects of United Nations Peace Operations.” The World Bank Economic Review 22:9-32.


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