While negotiating peace with justice requires the skills of an artist, some science is nevertheless involved. Part I demonstrated how that is so. First, we examined what makes ensuring justice for atrocity crimes more difficult, both normatively and practically, than for other crimes. Three imaginary country situations were presented: one in which there is neither negotiation nor transition out of war; one in which there is transition without negotiation; and one in which there is negotiation without transition. We explained how and why the latter presents the greatest structural constraints of all, in terms of ensuring justice.