A rise in number of trading partners leads to fewer wars between nations

Bob Yirka report

Source - http://phys.org/news/2015-12-partners-wars-nations.html

Credit: Tim Emerich/public domain

A pair of researchers with Stanford University has found via crunching economic and war data, that the more trading partners a country has, the less likely it will be to engage in a war. In their paper published in Proceedings of the National Academy of Sciences, the pair describes how they first attacked the problem from the reverse perspective, looking at data that showed an inclination to go to war in the absence of trade partnerships and how they were unable to find any correlations.
It is a well known in political circles that countries tend to not go to war with other countries that are their trading partners—doing so generally makes no logical sense. Also well known is the fact that the modern age has led (despite incessant headlines) to unprecedented low levels of warfare between countries. What is not really understood, however, is how much trading with partners actually impacts the numbers of wars waged. As the researchers note, prior studies have found that a large amount of trade with other countries is not necessarily a sign of a lesser likelihood of a country going to war—the period leading up to WWII, for example saw massive international trade.

To better understand correlations between international trade, military alliances and international wars, the researchers built a data network that used mathematical models to study the impact of international trade and wars to see if they could find any patterns—they report that in the absence of trade, alliances tended to shift frequently and easily leading just as easily to wars. When they switched the question to whether the number of trading partners had an impact on wars, they found quite the opposite. Most countries tended to not go to war with trading partners, and the more partners a country had, in general, the fewer wars they had. As an example, they note that back in 1870, the world's countries had an average of just three trading partners, today that number has climbed to between 17 and 34, depending on the exact definition of a trading partner.

The researchers believe their findings could be useful in avoiding wars in the future—if countries in the west, such as those in the U.S. and Europe, for example, built more trading relationships with places in the Middle East, then it might lead to fewer conflicts between the two regions.

More information: Matthew O. Jackson et al. Networks of military alliances, wars, and international trade, Proceedings of the National Academy of Sciences (2015). DOI: 10.1073/pnas.1520970112

Abstract 
We investigate the role of networks of alliances in preventing (multilateral) interstate wars. We first show that, in the absence of international trade, no network of alliances is peaceful and stable. We then show that international trade induces peaceful and stable networks: Trade increases the density of alliances so that countries are less vulnerable to attack and also reduces countries' incentives to attack an ally. We present historical data on wars and trade showing that the dramatic drop in interstate wars since 1950 is paralleled by a densification and stabilization of trading relationships and alliances. Based on the model we also examine some specific relationships, finding that countries with high levels of trade with their allies are less likely to be involved in wars with any other countries (including allies and nonallies), and that an increase in trade between two countries correlates with a lower chance that they will go to war with each other.