This is the second post in our series on politics, political science and the World Cup. In this post, Andrew Bertoli examines whether the World Cup incites nationalism that encourages political leaders to behave more aggressively in the international arena.

—Erik Voeten.

Although international sporting events were originally established to encourage peace between countries, there is substantial disagreement about how they actually affect interstate conflict. No doubt, the most popular view is that they reduce conflict by providing an outlet for nationalistic aggression and teaching countries to play fair and respect each other. This argument has been championed by many reporters, academics, U.S. presidents and international institutions.

However, others have contended that sports actually increase conflict between countries by inciting nationalism. Proponents of this view point to the 1969 Football War between El Salvador and Honduras and the 2009 Egypt-Algeria World Cup Dispute as clear examples of cases where sporting events resulted in conflict on the international stage.

The ideal way to address this question would be to run an experiment where we randomly selected a large number of countries to attend a major international sporting event and randomly chose others to stay home. We could then track the aggression levels of the treatment and control groups before and after the sporting event, much like we were medical researchers testing the effect of some new drug through a randomized controlled trial. These experiments are the gold standard for establishing causal relationships in most scientific fields, so the results from this type of study could significantly improve our understanding of how sporting events affect interstate conflict.

Although there has never been a real experiment that tests how sports influence state aggression, my new paper analyzes a natural experiment that is very similar to the ideal study described above. This natural experiment was created by the format of the World Cup qualification process from 1958-2010. Over this period, many countries qualified for the World Cup by playing a round of games against other teams and earning a top position in the standings. It is therefore possible to compare the group of countries that barely qualified to the group that barely fell short. The idea is that if Switzerland scored 15 points in the standings and qualified, while Portugal scored 14 points in the standings and missed, then it is basically a coin flip which of these countries went to the World Cup.

Using this idea, I constructed a sample consisting of 142 countries that barely qualified or barely missed qualification. I show in my paper that the qualifier and non-qualifier groups are very similar across a wide range of political, economic and demographic factors, which supports the idea that qualification was essentially random for these countries. They are also very similar on past levels of aggression. To quantify aggression, I use the standard measure of international aggression in political science, which is the number of Militarized Interstate Disputes that a state initiates. These disputes are instances where states explicitly threaten, display or use force against other countries. This measure is commonly in security studies, since interstate wars happen too infrequently to be a useful measure in most statistical tests.

The results show that going to the World Cup increases aggression substantially. The countries that barely qualified experienced a large spike in aggression during the World Cup year. The difference in the aggression levels between the two groups is statistically significant and very unlikely to have been caused by chance (p<0.01). The estimated treatment effect is also much larger for (1) countries where soccer is the most popular sport and (2) non-democracies, which have a history of using sports to generate public support for their aggressive foreign policies.

The qualifiers not only took military action more often than the non-qualifiers, but the actions they took tended to be more violent. The Militarized Interstate Dispute dataset codes for the highest level of action taken by each country, with one being the threat to use force and 20 being the start of interstate war. In the two years following the World Cup, the median for the qualifiers was 15, whereas the median for the non-qualifiers was 11. Moreover, the qualifiers were significantly more likely to launch a direct attack against another country (highest level of action=16). The Militarized Interstate Dispute dataset also codes for whether each dispute was intended to revise the status quo. In the two years following the World Cup, 72 percent of the disputes started by the qualifiers were revisionist, compared to only 54 percent for the non-qualifiers.

In my paper, I also replicate this analysis using the FIFA regional soccer championships like the European Football Championship and African Cup of Nations. Like before, I construct a sample of countries that barely made or missed qualification. In total, this new sample consists of 78 countries that barely made or missed their regional tournaments. The qualifiers and non-qualifiers were again well-balanced on aggression levels prior to qualification, but the qualifiers became significantly more aggressive following qualification. A full analysis of these results is available in my paper.

Although this data provides very strong evidence that international sporting events contribute to interstate conflict, these competitions may also have positive effects, like encouraging peace at the domestic level. For instance, in 2006 the civil war in the Ivory Coast was suspended after the national soccer team qualified for the World Cup. Similarly, Nelson Mandela used international sports to unify South Africa in the 1990s after the collapse of the apartheid regime. So even though international sports may create division between countries, they might also be able to forge a common identity within them, and this domestic stability could outweigh the costs at the international level. Thus, I do not believe that FIFA and other sports organizations should stop holding these competitions. However, they should recognize that pitting countries against each other on the international stage is unlikely to create feelings of peace and friendship between them.

Andrew Bertoli is a doctoral candidate in political science at the University of California at Berkeley. His research examines nationalism and war, with a focus on how surges of nationalism from sporting events lead to conflict.