Having explored the legal parameters of the criminal law of self-defence and challenges directed against the traditional application of the temporal rule, it is now important to explore the laws of war generally and the right to international self-defence within its historical context. As outlined in the Introduction, the advocates of the preventive war doctrine attempt to modify the right of international self-defence by way of discarding or relaxing the imminence requirement. For the purposes of this book, the core question is whether the right to self-defence must be altered in line with new historical or political exigencies; that is, whether or not the use of preventive force should be allowed against non-tangible threats. However, before placing an explicit focus on this question, we first need to survey the broader political and historical background out of which the contemporary law of international self-defence has developed. The main role of this chapter is thus to lay the groundwork for the subsequent analysis of the preventive war doctrine, which was, in large part, sought to be justified by reference to the customary roots of international self-defence. This chapter will sketch a historical and comparative context in which the just war principles of various traditions (principally the Islamic and the Christian) will be considered. This will clarify how the current prohibition on the use of force and its sole justified unilateral exception, international selfdefence, have matured within the matrix of international relations in accordance with practical necessities or political expediency. The historical analysis of the use of force discourse is imperative for a deeper understanding of

2 In spite of its horror and catastrophical consequences, the question of whether war can ever be eliminated from human affairs remains difficult to answer. “We all know we should eliminate war,” notes Hauerwas, “the problem is we cannot. Asking if we should eliminate war is like asking if we should eliminate sin. Of course we should, but the problem is that we cannot.” See S. Hauerwas, Should War Be Eliminated? Philosophical and Theological Investigations (Milwaukee: Marquette University Press, 1984), at 3.