War is costly, deadly and destructive. So, why do we do it? In his new book Why We Fight: The Roots of War and The Paths to Peace, Prof. Chris Blattman of the University of Chicago lays out the five main reasons why countries go to war—and why building peace is actually a lot easier than we may think.

Blattman is an economist and political scientist who studies global conflict, crime and poverty. As a seasoned peacebuilder, he has worked in a number of countries to help mitigate conflict between gang leaders, political enemies and ethnic villages. He argues that one of the keys to finding peace is using a tool called the bargaining range to give both sides a piece of what they want.

In this episode, Blattman discusses how wars come to be, the incentives to stop them and what it will take for Putin to stop the fighting in Ukraine.