Throughout this book I will discuss issues of global justice from two different perspectives. First, I will address global justice as a matter of morality, especially as a matter of moral fairness. Second, I will also address the issue of global justice from the perspective of international law as an emerging system of norms. This dual perspective calls for an interdisciplinary analysis where philosophical principles and legal practices are brought into conversation with each other as it were. I have employed this approach in my previous books on international criminal law. And I have benefited from employing historical materials from the Just War tradition, which provides a common core for both moral philosophers and international lawyers. In the current work I will also draw much guidance from the historical case of Magna Carta and the debates in many countries about how best to understand and instantiate the rights of Magna Carta's legacy.

The debates about global justice typically concern economic distributive justice or criminal retributive justice. Both of these forms of justice concern substantive justice, namely they concern the substantive rights that people have by virtue of either their economic need or their status as victims. I wish to discuss a third subject matter in the field of global justice, namely the procedural rights that constitute an international rule of law. I will contend that procedural rights provide a moral core to any system of law, and this is even more the case at the international level than at the national level. Such procedural rights provide at least minimalist protection concerning substantive rights as well. In this respect, the moral content of the natural law may very well be best exemplified in the institution of the rule of law. Any substantive rights can be held hostage if the person who would claim these rights can be incarcerated unjustifiably.