Borderlands violence, so explosive in our own time, has deep roots in history. Lance R. Blyth's study of Chiricahua Apaches and the presidio of Janos in the U.S.-Mexican borderlands reveals how no single entity had a monopoly on coercion, and how violence became the primary means by which relations were established, maintained, or altered both within and between communities.     For more than two centuries, violence was at the center of the relationships by which Janos and Chiricahua formed their communities. Violence created families by turning boys into men through campaigns and raids, which ultimately led to marriage and also determined the provisioning and security of these families; acts of revenge and retaliation similarly governed their attempts to secure themselves even as trade and exchange continued sporadically. This revisionist work reveals how during the Spanish, Mexican, and American eras, elements of both conflict and accommodation constituted these two communities, which previous historians have often treated as separate and antagonistic. By showing not only the negative aspects of violence but also its potentially positive outcomes, Chiricahua and Janos helps us to understand violence not only in the southwestern borderlands but in borderland regions generally around the world.