Just war theory (Latin: "jus bellum justum") is a doctrine, also referred to as a tradition, of military ethics studied by military leaders, theologians, ethicists and policy makers. The purpose of the doctrine is to ensure war is morally justifiable through a series of criteria, all of which must be met for a war to be considered just. The criteria are split into two groups: "right to go to war" ("jus ad bellum") and "right conduct in war" ("jus in bello"). The first concerns the morality of going to war, and the second the moral conduct within war. Recently there have been calls for the inclusion of a third category of just war theory—"jus post bellum"—dealing with the morality of post-war settlement and reconstruction.