INTRODUCTION

When after the Napoleonic wars of the early nineteenth century the Prussian major-general Von Clausewitz famously wrote that war was the continuation of policy by other means, he had a point. Throughout the ages, war had been conducted without many legal obstacles being placed in its way, and there was a strong sentiment that going to war, for whatever reason, was perfectly legal. Admittedly, many felt that this was an undesirable state of affairs, and theologians and lawyers alike had aspired to limit the possibility of resorting to war by making a distinction between just wars and unjust wars, but state practice had proved rather resilient. And understandably so: distinguishing between just and unjust wars presupposes a working conception of justice, and since justice is itself a highly contested concept, it follows that reasonable people could disagree about whether a war would be just or unjust.

Earlier generations of international lawyers insisted on a rigid distinction between war and peace; the two would be entirely different conditions, governed by different sets of rules. Some of this is still visible in today's international law; there are specific rules on how to behave during war (such as the 1949 Geneva Conventions) which have little application during peacetime. Still, the rigidity of that earlier distinction no longer applies; war and peace have come to be seen as more fluid conditions, sometimes governed by specific rules, but sometimes also by general rules. There is little doubt, for instance, that human rights law continues to apply even in wartime.