Political Scientists Show that UN Peacekeeping Works, But Not Without Cost

Over the past few decades, United Nations peacekeeping has become an important way to respond to conflicts around the world, especially civil wars. Indeed, since 1990 there have been more than two dozen missions. Currently, the total number of peacekeepers deployed across the globe hovers around 100,000.  

Although peacekeeping often flies below the public’s radar, many policymakers have argued that these operations are an important way for the U.S. to avoid the consequences of civil wars, be they mass killing and genocide, terrorism, refugees, deadly infectious disease, or other problems. Peacekeeping provides a way for the U.S. to share this burden with others, rather than respond alone.  As stated by Bruce Jones, Brookings Institution expert on peacekeeping, in a recent testimony before the U.S. Senate, “UN peacekeeping is the only mechanism we have at our disposal that allows us to combine forces from every region in the world to tackle crises or conflicts wherever they occur.” 

Liberia, a former U.S. colony in West Africa, is a case in point. During the 1990s and 2000s, it suffered from devastating civil wars. All told, the violence left over 200,000 people dead and created upwards of 2 million refugees. It also threatened to destabilize its neighbors and led to heightened concerns that terrorist groups would find safe haven. Feeling the pressure to respond, the U.S. came to the brink of intervening in 2003, when it sent 2,300 marines to Liberia's coast. However, the U.S. avoided putting these boots on the ground because it was able to rely on UN peacekeeping.

This operation, dubbed UNMIL, deployed to Liberia with nearly 15,000 personnel. It was a complex mission that had many tasks, including overseeing the implementation of a peace agreement, disarming and reintegrating former fighters, protecting civilians, providing humanitarian relief, and overseeing elections. Although the mission was periodically rocky, it was largely deemed a success. In 2007, after it helped stabilize Liberia, the UN reported that UNMIL made “great strides in consolidating peace and promoting economic recovery.” Civil war has not since recurred. Liberia is no longer a source of refugees. Nor has it become a haven for terrorist groups.

Dwindling Support for UN Peacekeeping

However, listening to recent comments by some U.S. officials, you might not believe peacekeeping yields any benefits. Indeed, current attitudes about peacekeeping now appear overwhelmingly negative. The new U.S. Ambassador to the United Nations, Nikki Haley, even suggested that poor countries reap unfair profits when they offer troops for peacekeeping in return for about $1,000 per troop each month. The White House’s current budget also reflects this view. It plans on at least a 40 percent cut to UN Peacekeeping.

Of course, peacekeeping’s detractors often point to some very real issues with these missions. Sexual predation by peacekeepers has become a problem that has been widely reported on. And there have been some notable instances where peacekeepers have failed to save lives, such as in Rwanda and Bosnia. More recently, UN peacekeepers in Haiti have also been linked to a cholera outbreak.

What does the evidence say?

Given that political shifts within the U.S. are leading it to change its view on UN peacekeeping, it is worth looking more systematically at peacekeepings’ effects, both good and bad. One way to do so is through social science research. Fortunately, political scientists have been examining peacekeeping for over a decade, often using statistical methods. These studies have revealed that peacekeeping typically has three benefits. First, it shrinks the chances that a country that has suffered a civil war will have another. Second, it limits the spread of violence to neighboring countries. Third, it reduces the number of people killed, both civilians and armed combatants.  

Virginia Page Fortna of Columbia University wrote one of the most influential of these studies. She found that the presence of a UN mission decreased the risk of war recurrence, by around 70 percent, in countries that have recently emerged from civil war.

A follow-up study took another look at this question. It largely confirmed Fortna’s finding. It also found that missions reduced the chances for civil war recurrence, but only when they deployed after the fighting stopped. Peacekeeping was not shown to have the same salutary effect when missions began in the midst of war. At least not yet.

Scholars have looked at whether peacekeeping limits civil wars spreading to other countries. One study found that peacekeeping made it about 75 percent less likely that a civil war spread to a neighboring country.

A group of three researchers—Lisa Hultman, Jacob Kathman, and Megan Shannon—looked to see if a mission's size and composition is important. In their first study, they analyzed peacekeeping’s influence on civilian non-combatant deaths. They found that having higher numbers of military and police personnel led to fewer casualties. This group also published a study focusing on the combatant deaths. Once again, they showed that peacekeeping helps saves lives. This was an important finding because it showed for the first time that peacekeeping still helps, even if conflicts may be ongoing.

UN peacekeeping's ability to reduce violence was also reaffirmed by 2017 research. This time researchers were able to look more closely at where peacekeepers were sent within countries having a civil war. This study found that violence episodes were less severe when peacekeepers were present in high-risk locations.

However, other work has now confirmed a relationship between peacekeeping and transactional sex. This study documented that about 75 percent of females who had engaged in these practices in Monrovia, Liberia had done so with UN Peacekeepers. The authors also found that the presence of peacekeepers significantly raised the chances that a female would begin engaging in transactional sex. Startlingly, they estimate that that, “more than 12,000 women in Monrovia entered the transactional sex market who would not have done so in the absence of UNMIL.” Thus, even if peacekeeping typically saves lives, it can to also worsen sexual exploitation.

Ultimately, highlighting what research has to say about UN peacekeeping serves two purposes. First, by showing that it saves lives and stabilizes areas of US concern, though also contributes to serious social problems, this body of research can help citizens and their governments make more informed judgments about whether, on balance, UN peacekeeping is worth supporting. Second, for US policymakers who believe that UN peacekeeping remains a worthwhile investment, it forces them to think harder about practical steps that should  be taken to reduce its downsides while still maintaining its benefits.