Throughout history, the defense of or desire for territory has led to recurrent and severe conflict. States are prepared to fight, and individuals to die, even over land with little intrinsic value.

Depending on the method of measurement, statistical studies show that territorial disputes account for one-quarter to three-quarters of all wars. Moreover, explicitly territorial disputes are more likely to lead to war than other types of dispute, more likely to lead to recurrent conflict, and more likely to result in high fatalities if war occurs.

This policy memo gives fresh insights into conflicts arising through territorial behaviour, and explains why people may be willing to fight over territory even when the costs are high and the probability of success is low. It outlines conditions under which territorial aggression is more or less likely, and suggests new ways to avoid it. 

This policy memo is based on an academic paper “Grounds for War: The Evolution of Territorial Conflict” which appears in the winter 2013/14 issue of International Security. It was first published as a Belfer Center Policy Brief by the Harvard Kennedy School in March 2014.