If order is the attainable and justice the possible, then (re)conciliation is the desirable. Conciliation is future-focused in that it sees former enemies as partners in a shared future. Sometimes, particularly in intra-state conflict, it is reconciliation—building bridges between parties that have some shared past. In international conflict, it is more likely that the goal is conciliation, the mutual effort of both sides to overcome past hostility and reframe the relationship as one of partnership. If the fundamental goals of just war thinking are to promote international security and to protect human life, then conciliation does this by ameliorating the conditions that can lead to new or renewed violence.
Christian just war theory has a theological basis for reconciliation: love. Caritas, or love (charity), is the notion of brotherly regard. Love calls on individuals to protect their neighbors and may result in a self-defensive war or intervention on behalf of allies or the weak. Love may motivate just punishment, the righting of wrongs, and restitution for the victim. Love calls into question our motives, restrains our behavior, and foresees a better peace approximating the ideal: the City of God.
Although I believe that reconciliation based on caritas is important in individual human relationships and can be called on in some intra-state conflicts, it is a tricky notion for international affairs. The international system is based primarily on national interests, and unless interests are engaged, conciliation is unlikely at war’s end. In other words, among states common interests are the basis for conciliation. In most conflicts, enemies have a history of tension and competition, and have probably fought openly at numerous times in the past. In this scenario, a change in interests is the usual mechanism for conciliation to be possible. For instance, relational changes usually take a long period of time (e.g., the United States and Great Britain-Canada) or may require a shared threat to provide a context for shared interests (e.g., Cold War France and Germany).
Of course, in international life, justice might be a mechanism that helps change the socio-political context in such a way as to allow for a positive change in the relationship. Certainly, one outcome of the Nuremberg Trials was the effect the punishment of Third Reich leaders had on thawing relations between Germany and its neighbors. Acts of justice can provide vindication to the victims and provide the conditions wherein a change in the quality of relationship is possible. Imagine, for instance, that the Russian people overthrow the oligarchy of Vladimir Putin. A new democratic Russia might make a fraternal peace with its neighbors.
Idealists argue that forgiveness and mercy are the fulcra for conciliation in international affairs. There are good reasons to be skeptical. There are almost no examples in international life of heads of state asking for forgiveness from their neighbors, and resulting acts of conciliation among states. The reasons for this are numerous, but primary among them is the multi-causal nature of conflict and the recognition that states go to war because they feel that it is in their interest to do so. States are self-interested, and it is folly to expect them, except under the most unique of circumstances, to plea, “We were wrong, won’t you please forgive us?” Consequently, the mercy/forgiveness path to conciliation among states is improbable at best; however, conciliation is possible based on the evolution or reinterpretation of national interests.
So, what about the potential for some sort of conciliation between Ukraine and Russia? We are not just talking about amorphous collectives, but about the flesh-and-blood people of both countries as well as their respective institutions. The citizens of a victimized Ukraine may have to choose what Jean Bethke Elshtain calls “knowingly forgetting.” Elshtain, reflecting on the horrors of war like rape and genocide, suggested that the only way that victims and their children could have a healthy path forward was to accept that the violence and sins of the past were real (“knowing”) and yet not allow their future identity to be solely defined in terms of past victimhood. Victims have to choose to move forward, to “knowingly forget,” or consciously release the gravitational pull of past injustice. To a lesser extent, the grieving mothers of Russia may have to do the same.
At the political level, we do have a number of past examples of countries finding a way to renegotiate their futures. The Camp David Accords established a cold peace between Israel and Egypt after four decades of war. European nations figured out how to accept the German people back into European civilization after World War II, in part spurred by shared threats. After World War II, Japan sought to redeem itself through financial investment in its neighbors. Most accepted funding from Tokyo’s Overseas Development Corporation, although they bristle at the fact that Japan consistently refuses to acknowledge blame for its concentration camps, sexual slavery, racialism, and other crimes. Nonetheless, a cold peace is far, far better than the constant worry of war.
In conclusion, we need a just war approach to jus post bellum. How wars end is not just the provenance of the victor: it is something we all should care about. Ending wars well means establishing order in such a way that it is sturdy and enduring. Moreover, it lays the groundwork for efforts to establish justice and conciliation in pursuit of lasting peace.
 Paul Ramsey, War and the Christian Conscience, chapter 2; Augustine, The City of God (Cambridge: Cambridge University Press, 1994).
 There is a growing literature on domestic reconciliation, forgiveness, and intra-state change. For examples see A. Boraine et al, Dealing with the Past: Truth and Reconciliation in South Africa (Cape Town: IDASA, 1994); Brian Frost, The Politics of Peace (London: Darton, Longman, and Todd, Ltd., 1991); James L. Gibson and Amanda Gouws, “Truth and Reconciliation in South Africa: Attributions of Blame and the Struggle over Apartheid” in The American Political Science Review 93, no. 3 (September, 1999); Neil J. Kritz, ed., Transitional Justice: How Emerging Democracies Reckon with Former Regimes, vol. 2 (Washington, DC: US Institute of Peace, 1995); Dan Markel, “The Justice of Amnesty? Towards a Theory of Retributivism in Recovering States” in The University of Toronto Law Journal 49, no. 3 (Summer, 1999); Martha Minow, Between Vengeance and Forgiveness (Boston, Beacon Press, 1998); Andrew Rigby, Justice and Reconciliation (Boulder, CO: Lynne Rienner, 2001); Accomodating Individual Criminal Responsibility and National Reconciliation: The UN Truth Commission for East Timor” in The American Journal of International Law 95, no. 4 (October, 2001); Barbara F. Walter, “The Critical Barrier to Civil War Settlement” in International Organization 51, no. 3 (Summer, 1997).
 Interestingly, we can observe countries that experience significant regime change (e.g., in Latin America and Eastern Europe in the early 1990s) make public statements breaking with the past, but we do not see these countries ask for forgiveness or offer restitution to neighbors they have threatened or harmed.
 There is a relatively new literature championed by Glen Stassen and others called “Just Peacemaking.” Although most of its proponents are from the pacifist tradition, nonetheless the efforts of Stassen and his colleagues are to address the real-world dilemmas that bedevil areas of intractable conflict. For an introduction, see Glen Stassen, “New Paradigm: Just Peacemaking Theory” in Council of the Societies for the Study of Religion Bulletin (Spring, 1997).