ABSTRACT
The questions relating to law and the use of force clearly constitute the most contentious and frustrating areas of international law. Here the default assumptions discussed in Chapter 1 inevitably color the discussion because of the obvious comparison to domestic criminal law and states “breaking the law.” As with other areas, the issues are much more complex than that simple judgment. Historically, the law on the use of force has divided into two distinct categories: the jus ad bellum that presumably governed the resort to war and the jus in bello or the law governing individual conduct within war. This chapter addresses questions relating to the jus ad bellum, slightly redefined to mean the right to resort to force. Chapter 20 will cover the basics of the jus in bello and Chapter 21 will examine modern war crime trials.
