New Study Shows Alliances Go Beyond Signers of an Agreement

March 17, 2017

New Study Shows Alliances Go Beyond Signers of an Agreement

Skyler Cranmer

Even nations can have friends of friends, a new study has found.

Results suggest these indirect relationships have a surprisingly strong ability to prevent major conflicts, and that international military alliances may matter more than we typically expect.

Many studies have shown that nations with military alliances are less likely to go to war. But this new study is the first to show that neighboring countries without direct alliances are still unlikely to have serious conflicts, as long as they are indirectly connected through an ally in common.

In fact, this peace dividend extends up to three degrees of separation without getting weaker: Nations are much less likely to have wars with their allies, the allies of their allies, and the allies of their allies' allies.

"The peacemaking impact of an alliance between two countries goes beyond the two that signed the agreement," said Skyler Cranmer, lead author of the study and the Phillips & Henry associate professor of political science at The Ohio State University.

"It permeates the network of alliances, like ripples in a pond, to prevent conflicts beyond the two countries that have the alliance."

The researchers were surprised that the strength of these indirect relationships didn't decline until they went beyond three degrees, said co-author Aisha Bradshaw, a Ph.D. candidate in political science at Ohio State.

"We didn't expect that. We thought the effect would decline with each degree of separation," Bradshaw said.

The study was published in the journalĀ Science Advances and was also featured on The Conversation. Ph.D. candidate Caitlin Clary was also a co-author of the study.