The ethics of peace developed by Karl Barth (1886–1968) and his Mennonite pupil John H. Yoder (192701997) provides orientation for today’s churchly and ecumenical debates about Christian Pacifism and Christian Just War Tradition. Hofheinz’ study reconstructs and reassesses the christological basis of Barth’s and Yoder’s endeavor. It asks for the relevance of central theological themes like the meaning of Christ’s name, communitarian freedom, prayer, and salvation in Christ. Furthermore, it compares Barth’s and Yoder’s concept of following Jesus. Hofheinz illustrates Barth’s and Yoder’s respective understandings of just war theory and its application to the debate over nuclear war and the so-called borderline case. The study develops important ethical impulses for a Christian agenda in a warring world.