In the previous chapter, the conclusion was reached that a theory on conflict of norms could not be established with reference only to the sources of norms. Instead, we focused on the norms themselves, distinguishing general from particular international law norms. In this chapter, we examine the different functions of norms of international law, how these norms may interact (contrasting accumulation versus conflict of norms) and what the outcome of such interaction can be (focusing, in particular, on the processes of ‘fall-back’ and ‘contracting out’ of general international law).

The function of norms

Most norms of international law have one of four functions:

1. They impose an obligation on states to do something, that is a COMMAND (so-called ‘prescriptive norms’, ‘must do’ or ‘shall’ norms or norms imposing a ‘positive’ obligation);

2. They impose an obligation on states not to do something, that is a PROHIBITION (so-called ‘prohibitive norms’, ‘must not do’ or ‘shall not’ norms or norms imposing a ‘negative’ obligation);

3. They grant a right to states not to do something, that is an EXEMPTION (so-called ‘exempting’ norms or ‘need not do’ norms); or

4. They grant a right to states to do something, that is a PERMISSION (so-called ‘permissive norms’ or ‘may do’ norms);