In our troubled times of global conflict, philosophical reflection on war and peace has never been more urgent. This distinctive contribution to the ethics of war combines pragmatism with Kantian-inspired transcendental philosophy to offer fresh insights into age-old questions of when, if ever, war can be ethically acceptable. Sami Pihlström argues that both traditional just war theory and pacifism function as forms of "secular theodicy", which justify innocent suffering for supposed greater goods. Moving beyond these approaches, he develops a meliorist framework that refuses both naive optimism and fatalistic pessimism about human conflict. The book examines three critical areas: the problem of sacrificing innocents in war, the ethics of nuclear deterrence in our post-World War II world, and the philosophy of history that shapes how we understand ourselves as a political community. Central to this analysis is the concept of defending the "transcendental 'us'"—not merely a contingent nation-state, but the very conditions that make ethical and political community possible. Drawing on thinkers from William James to Raimond Gaita, this work offers a philosophically rigorous yet accessible exploration of what it means to defend civilization itself against existential threats, ensuring that those who die in such defense "shall not have died in vain."War, Pacifism, and Deterrence will appeal to researchers and graduate students interested in the philosophy of war and peace, pragmatism, and transcendental philosophy.