The 20th century has witnessed an unprecedented expansion in the international protection of human rights. Analysis demonstrates that such protection can be viewed as a continuum along which criminal proscription has become the "ultima ratio" modality of protection. Report to criminal proscription is compelled when a given right encounters an enforcement crisis in which other protection modalities appear inadequate. Yet, the need to find an international or transnational element in human rights violations, along with the need to rely on national courts to implement international penal proscriptions, represents impediments to scrutinizing violations committed by officials of sovereign States. The challenge is to find justifiable limits on international criminal law and discover how best to utilize international criminal law to prevent and suppress human rights violations. Despite the world community's growing awareness of the need to protect common values and human rights, the achievement of such protection has been elusive. Possibilities for more effective protection can be enhanced by clarifying relations between fundamental values and criminal and alternative enforcement modalities. 120 footnotes