INTRODUCTION

The previous chapter discussed in some detail when states can legally use force, and held that nowadays they can do so either under the banner of collective security (with UN Security Council authorization) or in self-defence. Classically, the law relating to the right to wage war is known as the jus ad bellum, and it has occupied philosophers and lawyers for centuries. In much the same way as there are rules on when force can be used, there are also rules on how force can legally be used: jus in bello. Some even go so far as to say that the phase of reconstruction after hostilities have come to an end is subject to a special legal regime: jus post bellum. The jus ad bellum has been discussed in the previous chapter; the current one will be devoted to the jus in bello and, to a limited extent, to the emerging jus post bellum.

As the previous chapter also suggested, the distinction between war and peace is not nearly as clear cut as it once may have been, and the term ‘war’ itself is often avoided, on the theory that it is too politically loaded. War is rarely declared these days (if at all), and armed hostilities can come in varying grades of intensity, ranging from minor boundary incursions to full-blown attacks. As a result, it is difficult to say where peace ends and war begins. Moreover, it is no longer considered to be the case that peacetime rules are more or less automatically suspended once hostilities break out; certainly the fact that Iraq and the USA are at war does not affect their membership of the UN, and nor does it suspend their obligations under human rights conventions or environmental treaties.