Any reasoned analysis of the present international system must conclude that the early decades of the twenty-first century will be marked by considerable instability and conflict (1, 2). The gap between the minority rich and majority poor of the world is already immense and likely to widen, and population growth in poorer, resource-deficient regions will not come under control for some time yet.
In addition to these underlying drivers of instability, one net result of the long East-West Cold War in the second half of the twentieth century was to flood conflict-prone regions of the developing world with the weaponry that will continue to exacerbate the conflicts that arise there. To make the situation potentially even more unstable, another consequence of the vast expenditure of resources on weapons development by the rich world over the past fifty years has been to produce what is called a “revolution in military affairs” (RMA) (3). We do not need to discuss the details of this revolution here, but we should note that its key characteristics include the application of modern information technology to weapon systems and their use. In one sense, as seen in the wars in the Gulf in 1991 and the former Yugoslavia in 1999, this leads to the capability for much more discriminating use of force (4). However, it has to be accepted that advanced weapon systems such as cluster bombs can have immense destructive power, and the capability to target numerous discriminating weapons at the same place at the same time can lead to enormous devastation. So the development of the RMA does not necessarily imply that wars can be fought with few casualties and little damage. Indeed, it could well be that the very opposite is the case in certain circumstances.
Whatever the developments in technology, though, it has been acknowledged since the nineteenth century that any state's right to wage war is not unlimited. The most recent statement of this principle was made in