What is the risk of a war on the Korean peninsula or South China Sea? Or, for that matter, of another terrorist attack on American soil? These are questions that western diplomats and security experts are asking themselves this spring. And as speculation grows, those officials have been duly scouring satellite feeds, intelligence reports and history books.

Over in Colorado, Aaron Clauset, a computational scientist, is pondering the dangers from a different perspective. Clauset, who teaches at the University of Colorado, Boulder and is part of the Santa Fe Institute, has spent the past decade on the frontier of computing and statistical research. But he has not focused on areas normally beloved by geeks, such as engineering, physics or biology.

Instead, Clauset and other statisticians, such as Ryan Woodard of the Swiss Federal Institute of Technology in Zurich, have analysed the past 200 years of military conflicts. And this has produced a thought-provoking conclusion: if you look at the global pattern of war and terrorism, human violence has moved in surprisingly stable cycles.