A feature of the First World War, was the consistent condemnation of it by Pope Benedict XV and his unsuccessful efforts to bring about a negotiated peace. This paper argues that the Pope realised that the nature of modern warfare demanded a new evaluation of war and that his teaching began a real shift and development in this teaching that is clearly discernible in the teachings of his successors and the Second Vatican Council, and the work of Catholic theologians and movements. However, we can see how in many ways this shift has not been recognised in the wider church, shown by the reluctance of local church leaders to question or condemn particular conflicts. On the basis of this shift the paper argues that the Catholic Church, now committed to “virtual pacifism”, should base its witness to peace on two paradigms: first, the unmasking of wickedness, seen above all in the culture engendered by the possession of nuclear weapons; and second, a marked distancing from the powers and claims of the modern nation state.

The election of Giacomo Della Chiesa as Pope Benedict XV coincided with the outbreak of the First World War. His pacifism led to vigorous attempts to halt the war, which failed because of the Vatican's isolation and poor diplomatic prestige. The most notable attempt was Benedict Peace Note of 1917 that set out seven proposals for negotiating peace. Despite Benedict's failure to alter the course of the war, his diplomatic efforts were matched by humanitarian action on behalf of prisoners of war and famished children. Benedict's legacy has been greater diplomatic resources for the Vatican and an energetic search for peace.

This paper describes the background to the last fifty years of violence in Columbia and identifies its causes in inequality, poverty and displacement. It then explores the ways in which the Catholic Church has been prominent in developing processes of peace-building that include “accompaniment” of the victims to include them in structures of citizen participation. It ends with theological and pastoral reflections on how this can be enabled practically in the Columbian context.

This essay falls into two parts. In the first I offer a panorama of my book, In Defence of War (Oxford University Press, 2013), highlighting its main features. These comprise: its rhetorical position; its opposition to the “the virus of wishful thinking”, pacifism, legal positivism, and liberal individualism; and its promotion of the early Christian tradition of just war reasoning and of three kinds of realism – moral-ontological, Augustinian-anthropological, and practical. Then in the second part, I consider four controversial issues that the book raises: love, proportionality, Britain's entry into the First World War, and the 2003 invasion of Iraq.

The classic, theological tradition of just war reasoning (JWT) is not exhausted but needed more than ever in the shadow of global risks, when facing “hybrid” war, and when the difference between war and peace is said to be blurring. The tradition does not speak with one voice but debate within the tradition about the (un)acceptability of military action under conditions of uncertainty sheds light, in at least three ways, on ways of approaching the range of unorthodox tactics threated in conflict today:

1. 1. How to be fearful. Fear and anxiety in an age of risk are potential threats to reason. The JWT has resources with which to consider “how to fear” wisely.

2. 2. How to grapple with issues of classification, including what constitutes an attack equivalent to an “armed attack” under UN Charter Art 51. When, for instance, are cyber-attacks better dealt with under civilian, international commercial law, and when the laws of war?

3. 3. How to approach new challenges in a principled manner. Are different principles or criteria needed to govern action (e.g., the criterion of intensity) or do immediacy and necessity remain the most critically important principles in our moral arsenal?

The role of combat as a religious stimulant was widely observed and debated during both World Wars. Through a consideration of American opinion in World War II, especially in the light of British opinion a generation earlier, this paper illustrates that, however similar expressions of combatants’ faith may have been across time and space, their perceived value was very much dictated by their wider religious context, and particularly by the existing assumptions and priorities of religious observers and pundits. This meant that, in the American context of World War II, appraisals tended to be much more positive than in the British context of World War I, adding considerable substance and longevity to the claim that ‘there are no atheists in foxholes’.

This article, “reflects back and works forwards”, by thinking together the three “sorrowful mysteries” of the last one hundred years; three marked and irrevocable steps of escalation and complexity in the history of international conflict. Along with so many others in this centenary year, we commemorate: its causes, and the lessons to be learned. What are the continuities between the Great War, 1914–18, and the second “sorrowful mystery”, the advent of nuclear weapons? This brings us to the specific challenges that face us in the present: globalized violence in the name of religion, the reactive “war on terror” and the development of “smart” technology, remind us that our context too is unprecedented and uniquely dangerous. Explanatory avenues opened up include discussion of the moral and political implications of unmanned weapons, or drones. Here is an example of the crisis of sacrifice associated with René Girard, while Girard's own recasting of Clausewitz's notion of the “escalation to extremes”, and the humanism in Edward Schillebeeckx are also examined.