Democracy requires a commitment to dialogue and deliberation, as well as a commitment to seek peaceful solutions. Is democracy possible in states that earn significant portions of their revenue from the manufacture and sales of arms, that give weapons away in huge numbers, and that turn quickly to violence in the face of difficulties? The proliferation of weapons is nearly as great a tragedy of the commons as global warming, and the evidence indicates that civilians are increasingly being targeted in wars. How large is the problem of war today? Given that the members of the UN Security Council are among the chief manufacturers of weapons, are there any useful mechanisms in place for limiting wars or the supply of deadly weapons? Is it time, in view of the callousness with which non-combatants are killed, to re-examine our basic reasons for valuing human life? Cain's Crime re-introduces an ethical theory popular at the dawn of the twentieth century and examines the extent of violence in the contemporary world, from neo-colonial wars, civil wars, freedom movements, and ethnic conflicts to the oldest war of all, the systematic and continuing murder of women in cultures where they are valued less than men.