ABSTRACT
The questions relating to law and the use of force clearly constitute the most contentious and frustrating areas of international law. Two thousand years ago, Cicero simply stated that “in war the laws are silent.” 1 More recently, a prominent law professor expressed the frustration felt by many over what she perceived as the limitations of law in dealing with a modern tragedy: “How can an effort so broadly supported in its objectives-to stem Belgrade’s expulsion of ethnic Albanians from Kosovo and block a gross violation of international law-be so uncertain in its legal basis?” 2 This chapter takes a broad view of the basic problems. The range of conflicts where states have resorted to force extends from responses to terrorism and/or transboundary guerrilla raids, to “cod wars” over fishing rights (Iceland and the United Kingdom) to classic invasions (Iraq and Iran, Vietnam and Cambodia). In this respect, we need to emphasize that the Charter of the United Nations (Article 2(4)) prohibits the unilateral use of force by member states (states parties), not just the resort to war. 3
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 primarily addresses questions relating to the jus ad bellum, slightly redefined to mean the right to resort
to force. 4 Chapter 21 will cover the basics of the jus in bello and Chapter 22 will examine modern war crime trials. In particular, the discussion will emphasize the importance of defining contexts. From the discussion earlier, one should quickly understand that the phrase “use of force” contains a legal minefield. Consider how many different descriptions of conflicts appear in the contemporary literature discussing various situations in which force has been used. In addition to war, one finds civil war, internal armed conflict, international armed conflict, humanitarian intervention, hostilities, and police actions, to name just a few.
