Introduction

Gerald Neuman starts an important essay as follows: “Two leading systems exist today for protecting the fundamental rights of individuals: constitutional law and [international] human rights law.…For liberal states that actively enforce constitutional norms, the relationship between these two systems assumes increasing importance.” Neuman explores this relationship by focusing on the institutional consequences and mutual interactions of the two systems.

In trying to both clarify and evaluate the role of human rights law in discussions about international constitutionalism, my focus in this chapter will be less on the relationship between these two legal systems than on their differences and respective functions. I will ask and address two threshold questions. First, how different are the two systems? Second, why have both systems?

Whatever the general degree of analogy or dissimilarity between constitutional law and international law, domestic bills of rights and international human rights law undoubtedly perform the same basic function of stating limits on what governments may do to people within their jurisdictions. Indeed, in “liberal states that actively enforce constitutional norms,” international human rights law tends to place similar limits on the very same governments. So what are the major differences between the two beyond the obvious one of source? In particular, is there anything “constitutional” about international human rights law? Should one conclude from the similarity of function and substance that international human rights law is primarily meaningful in, or addressed to, nonliberal or non-Western states?