This book argues power balances, rather than shared identities, explain why warring Afghan groups aligned with and double-crossed each other.This book explains why Afghan warring groups constantly aligned with and double-crossed each other, and develops a theory on such behaviors in multiparty civil wars in general. It shows that intergroup alliances and intra-group fractionalization are determined by the distribution of relative power among warring groups, rather than by ethnicity, race, ideology, or religion. This book uses interviews with warlords, mujahedin, and convicted war criminals, among others, in Afghanistan and Bosnia, and tests its claims against fifty-three cases of multiparty civil wars.This book explains why Afghan warring groups constantly aligned with and double-crossed each other, and develops a theory on such behaviors in multiparty civil wars in general. It shows that intergroup alliances and intra-group fractionalization are determined by the distribution of relative power among warring groups, rather than by ethnicity, race, ideology, or religion. This book uses interviews with warlords, mujahedin, and convicted war criminals, among others, in Afghanistan and Bosnia, and tests its claims against fifty-three cases of multiparty civil wars.Some of the most brutal and long-lasting civil wars of our time those in Afghanistan, Bosnia, Lebanon, and Iraq, among others involve the rapid formation and disintegration of alliances among warring groups, as well as fractionalization within them. It would be natural to suppose that warring groups form alliances based on shared identity considerations such as Christian groups allying with Christian groups, or Muslim groups with their fellow co-religionists but this is not what we see. Two groups that identify themselves as bitter foes one day, on the basis of some identity narrative, might be allies the next day and vice versa. Nor is any group, however homogeneous, safe from internal fractionalizatil“Õ