The sixth chapter applies the analytical framework for due diligence obligations to the field of human rights protection. The individual components of due diligence obligations are analyzed with regard to the specific risks and problems of human rights law. It addresses how knowledge of human rights risks can be established, how resource constraints alter human rights obligations in times of conflict and economic recession, and what reasonable measures of protection are required. Conclusions from the previous chapter are consulted in order to decide whether due diligence concepts and methods developed in other fields of international law might be fruitfully applied to the area of human rights protection. When analyzing the application of human rights due diligence obligations though, the chapter will also reveal that the implementation of such obligations is often hampered where states lack sufficient capacities to effectively regulate and control harmful non-state conduct.

The seventh chapter addresses extraterritorial due diligence obligations which impose upon capable states a duty to regulate harmful conduct of non-state actors operating abroad. In a first step, the chapter explains that such obligations are not generally incompatible with international law and do not infringe upon the principle of non-intervention. It is further suggested that they could even be qualified as mandatory under certain circumstances and states should diligently regulate extraterritorial conduct where they have a sufficient jurisdictional nexus. The chapter concludes with an investigation of two extraterritorial constellations in which such obligations could contribute to more effective human rights protection: the trade of arms and the activities of multinational corporations. Recent examples of domestic legislation such as the 2017 French Law on Duty of Care underline that state practice is emerging which supports the claim for accepting extraterritorial human rights obligations and provides guidance for future action.

Embedded in this analytical framework, the fifth chapter is dedicated to an analysis of how due diligence obligations are applied and implemented in different areas of international law. Since the standard of due diligence is highly context-specific, problems and prospects related to its application are best illustrated by taking a closer look at the standard’s implementation in concreto. To this end, three fields of international law are singled out in which due diligence obligations have already been prominently discussed and which show certain similarities to the area of human rights law: the protection of the environment, the fight against terrorist activities, and rather recently the combat against harmful cyber activities. Based on the analytical framework introduced in the previous chapter, the application of due diligence obligations is discussed for each field taking into account the relevant state practice, international jurisprudence, and scholarly writings.

The fourth chapter develops an abstract analytical framework of the different components of an international due diligence standard. It seeks to deduce those elements which due diligence obligations contain generally and irrespective of their application to specific fields of international law. With knowledge, capacities, and reasonableness three major components are identified: If a state knows of potential violations of international law, it is obliged to employ the reasonably available means at its disposal to prevent such violations or to sanction them should they occur nonetheless. The chapter then discusses common problems inherent in the application and implementation of due diligence obligations. Most notably, it elaborates on how the foreseeability threshold might be overcome; how the problem of diverging capacities could be addressed and whether all states have to adhere to the same standards of diligence; and finally how the vague and broad notion of reasonableness can be given substantial meaning.

In order to discuss how the rules on state responsibility may be adjusted to better address human rights violations by non-state actors, it is essential to analyze what concrete responsibilities are to be derived from international human rights law. It is against this background that the second chapter starts by reviewing existing human rights typologies and discusses why – even though these typologies foster the understanding of the historical development of human rights and different human rights categories – they do not provide any further insights on the concrete content of human rights obligations and the circumstances under which state responsibility for human rights violations might be triggered. Therefore, the second chapter proposes a different typology of human rights which is oriented toward the concept of state responsibility. It takes a closer look at what precise obligations might be taken from international human rights obligations and how those obligations could be typologized.

The growing importance of non-state actors challenges the traditional inter-state order of public international law. In many respects, the reciprocal logic undergirding state responsibility is difficult to apply and high thresholds for attributing non-state conduct complicate matters even further, which stands in stark contrast to the increase in power on behalf of non-state actors, in particular where they operate in countries that lack the capacities to effectively regulate and control private actions. International law’s traditional way to fill these accountability lacunae has been the recognition of due diligence obligations that require states to diligently prevent and sanction harmful private conduct.

The first chapter introduces the broader debate on human rights and non-state actors. With the political and economic power of non-state actors ever increasing, the creation of directly binding international human rights obligations for non-state actors, in particular for multinational corporations, has become a popular suggestion. The chapter discusses why such direct obligations cannot be derived from the existing human rights system and weighs arguments in favor and against creating such obligations in the future. It emphasizes risks and problems that are critical but often overlooked in this context and concludes that direct human rights obligations for non-state actors neither seem feasible nor politically desirable which makes it necessary to look for alternative solutions in order to address the increasing problem of human rights violations caused by actors other than states. Due diligence obligations on behalf of states may present such an alternative.

There has been much debate in recent years about the role of non-state actors in international law. Whereas their presence is undisputedly acknowledged, their status and legal accountability remain unsettled. In many areas of public international law, harm is now significantly often caused by actors other than states. Terrorist groups threaten the territorial integrity of states; private security companies are involved in armed conflicts; individual hackers initiate cyber-attacks; and multinational corporations cause transboundary environmental harm or business-related human rights violations. Nonetheless, international treaties and customary international law still assign rights and duties almost exclusively to states.

In order to narrow down the concrete content of an international due diligence standard, the third chapter starts with a brief historical summary of how due diligence obligations have entered the international stage. It retraces how the standard of due diligence has been developed in early scholarly writings before it was widely applied in the jurisprudence of so-called Claims Commissions in the context of alien protection laws. In spite of this early recognition, several codification attempts yet have failed which is why the standard of due diligence is not entailed in the ILC’s draft articles on state responsibility that mirror the modern status quo of the customary law on state responsibility. In a second step, chapter 3 therefore undertakes an attempt to locate the position of due diligence obligations in the existing law on state responsibility by comparing and contrasting the standard with other concepts of responsibility.