The Impact of International Military Interventions on the Intensity of Conflicts

Abstract

Over the last two decades, much has been written about international military interventions. This literature has primarily focused on how interventions affect the duration of a conflict or the outcome of a conflict. This thesis attempts to look at a new dimension that interventions have an effect on—the intensity of a conflict. Operating under a rationalist view on war, I hypothesize that interventions decrease the intensity of conflicts because they act as a shock to the calculations that sides made when deciding to begin a war. As the sides realize the intervener increases the probability of victory for one side, the sides decrease the intensity of conflict and seek an alternative resolution. To test whether and to what extent interventions affect the intensity of conflicts, this thesis uses an interrupted time series and compares the trends in the intensity of the conflict before and after the intervention. It looks at all interventions that occurred in all conflicts between 1945 and 1999. Using two different selection processes for deciding which of these interventions to analyze, it then analyzes the effect of interventions controlling for regions and time periods. The data suggests that interventions, in general, do decrease the intensity of conflicts. This finding was fairly constant despite looking at how effective interventions were in certain regions and decades. An interesting finding was that during the 1960s and 1970s, interventions did not have as great of an impact, which could be attributed to the Cold War superpowers’ involvement in global affairs. Countries may have anticipated a possible intervention when they decided to go to war, which might have mitigated the effect an intervention had. Also, it seems like in some regions, such as Sub-Saharan Africa, the intensity of the conflict jumps to an unexpectedly high level when interventions occur. This could suggest that interventions there are either done for the wrong reasons and make the conflict worse, or these countries adversely react to an outside influence. Looking at various case studies further supports the hypothesis that interventions reduce the intensity of a conflict by changing the probability of victory for each side of a conflict. From these results, it can be concluded that interventions are generally an effective policy tool for reducing the intensity of a conflict. However, these interventions must be backed by a certain amount of commitment to intervene until the conflict abates. The most successful interventions were the ones, which increased their involvement until it was clear that the unsupported side would lose, forcing them to the bargaining table. However, these findings do not fully support an assertive foreign policy that intervenes in every conflict. On the contrary, these findings would suggest a policy of rarely intervening is more effective because sides in a conflict would not be able to anticipate the intervention and thereby negate its effect.