War, as Carl von Clausewitz taught us, is political in nature. War, as Sir Michael Howard reminds us, is the norm in international politics, not the exception. War is ancient, inevitably brutal and will not go away. It must be dealt with in political terms and deserves our constant reappraisal. ‘Politics will, to the end of history, be an area where conscience and power meet,’ wrote the theologian Reinhold Niebuhr in 1932, ‘where the ethical and coercive factors of human life will interpenetrate and work out their tentative and uneasy compromises.’ War and peace decisions are among the most important choices facing politicians in a democracy.

The just war tradition, as George Weigel discusses in this volume, is a way of thinking about war and peace that must be understood within a wider theory of responsible statesmanship. It has found its applications in the past, as James Turner Johnson argues in this volume and elsewhere, not only in the theological seminaries and ethics classrooms but in international law and in the behaviour of armed forces. To reflect on the just war tradition is to reflect on the use of power in the world. This reflective chapter poses the question, What does that tradition suggest for the twenty-first century?

Historical lessons

In answering the above question we must be careful to dwell neither exclusively nor excessively on today's headlines.