India, July 2 -- Conflicts from Ukraine to the Middle East persist in part because once-promising peace deals have unravelled. The war in Ukraine has endured despite successive Minsk agreements, just as the Israeli-Palestinian strife persisted even after the Oslo Accords. Renewed tensions over Iran's nuclear ambitions followed the collapse of the Joint Comprehensive Plan of Action (Iran-US nuclear deal). Yet not all treaties founder: the Good Friday Agreement has largely silenced decades of violence in Northern Ireland, and the 1994 Israel-Jordan peace treaty remains steadfast. How significant are peace agreements? What is the cost of their failure? And why do they often fail in the first place? HT has looked at the numbers in detail.

Pu...