International environmental law rarely refers to the rule of law. However, in fostering inter-state cooperation, international environmental agreements oblige parties to prohibit, restrict or control various activities that are harmful to the environment. The application of these constraints at the national level requires the rule of law to be taken into account.

Taking a law-and-governance approach, this article addresses legal certainty in international human rights law as it applies to artificial intelligence (AI). After introducing key issues concerning legal certainty, a comparative analysis of AI law-and-governance initiatives at the international, regional and national levels is undertaken. The article argues that many initiatives contribute to increased legal certainty and can partially compensate for some of the shortcomings of the international human rights law framework, but that further clarification is badly needed. This is especially true for the responsibilities of private businesses which are developing AI and the corpus of human rights beyond privacy and data protection.

Application of international treaty and customary international law at the Court of Justice of the European Union (CJEU) is increasingly recognized by scholars as problematic regarding legal certainty. This Article seeks to illustrate why this is and to propose reform. Through comparing judicial approaches in the application of international law at the CJEU to its approach in internal case law, it is argued that in the frequent absence of proportionality in external case law the Court has utilized, redeployed, or varied other judicial devices in an effort to retain the discretion which proportionality affords. These are argued to effect legal certainty and established concepts of justice within the EU legal system. Accordingly, it is submitted that proportionality should be transplanted fully and openly to external relations case law and that support for this can be extrapolated from existing literature.

The First Senate of the German Federal Constitutional Court (FCC) has recently introduced the express promise that where EU fundamental rights take precedence over German fundamental rights, the Court itself could directly review, on the basis of EU fundamental rights, the application of EU law by German authorities. There are, however, differences between the Basic Law as the relevant standard of review and other standards of review that are dangerous to ignore. The constitutional status of the FCC’s jurisdiction depends crucially on whether the Court relies on the constitution or on EU fundamental rights. If the constitutional status of the novel jurisdiction covered any binding-effect, and that is a big if, the FCC still would not safeguard the unity and coherence of Union law. Leaving aside the fact that the First Senate is confined to reversing and remanding (unable to enforce anything directly), no beneficial effect on legal certainty grows apparent. Any binding-effect of the novel jurisdiction only provides for consistency without finality. And to venture further into the question: Even if anyone welcomed this novel kind of consistency without finality (virtually “provisional consistency”), this oddish consistency would still be a localized consistency, i.e. in German courts only.

Here I reflect on the role of subjective or intentional elements in EU economic law prohibitions, particularly in relation to rules concerning public administration. From a normative perspective, it is desirable to suppress the need for an assessment of subjective intent and to proceed with an objectified enforcement of such prohibitions. With this in view, I consider public procurement and Member State aid rules as two examples of areas of EU economic law subjected to interpretative and enforcement difficulties due to the introduction – sometimes veiled – of subjective elements in their main prohibitions. I establish parallels with other areas of EU economic law – such as antitrust, non-discrimination law and the common agricultural policy – and seek benchmarks to support the main thesis that such intentional elements need to be ‘objectified’, so that EU economic law can be enforced against the public administration to an adequate standard of legal certainty. This mirrors the development of the doctrine of abuse of EU law, where a similar ‘objectification’ in the assessment of subjective elements has taken place.

I draw on the case law of the Court of Justice of the European Union to support such ‘objectification’ and highlight how the Court has been engaging in such interpretative strategy for some time. The paper explores the interplay between this approach and more general protections against behaviour of the public administration in breach of EU law: the right to good administration in Article 41 of the Charter of Fundamental Rights of the European Union and the doctrine of State liability for infringement of EU law. I conclude with the normative recommendation that the main prohibitions of EU economic law should be free from subjective elements focused on the intention of the public administration.

One of the key functions or purposes of international law (and law in general for that matter) is to provide long-term stability and legal certainty. Yet, international legal rules may also function as tools to deal with non-permanent or constantly changing issues, and rather than stable, international law may have to be flexible or adaptive. Prima facie, one could think of two main types of temporary aspects relevant from the perspective of international law. First, the nature of the object addressed by international law or the ‘problem’ that international law aims to address may be inherently temporary (temporary objects). Second, a subject of international law may be created for a specific period of time, after the elapse of which this entity ceases to exist (temporary subjects). These types of temporariness raise several questions from the perspective of international law, which are hardly addressed from a more conceptual perspective. This volume of the Netherlands Yearbook of International Law aims to do exactly that by asking the question of how international law reacts to various types of temporary issues. Put differently, where does international law stand on the continuum of predictability and pragmatism when it comes to temporary issues or institutions?

The rule of law has emerged both on the domestic and international levels as a promise of longstanding democracy, economic development and peace. On both levels, the rule of law is often associated with the longstanding character of institutions and the predictability of rules, meaning that ‘citizens are entitled to laws that are neither murky nor uncertain’. However, does this always mean in practice that the rule of law can only be concretized by laws and legal institutions that last forever? More specifically in the international context, can we guarantee the consolidation of the international rule of law through the coexistence of both permanent and temporary institutions and instruments? In this chapter, I analyse the meaning of the rule of law at the domestic and international levels and discuss its complex relationship with time. I argue that the past, present and future of the rule of law can be, in some cases, united by the use of temporary institutions such as international criminal tribunals or truth commissions, rules and measures. Temporariness can be essential to react swiftly to humanitarian crises, provide transitory justice, gradually concretize the rule of law in fragile democracies, and adapt legal orders to evolving economic and political circumstances.

On 22 November 2005 the European Court of Justice (hereafter, the Court) rendered its Mangold-ruling on Council Directive 2000/78/EC of 27 November 2000 establishing a general framework for equal treatment in employment and occupation (hereafter, Directive 2000/78). The most striking part of this judgment, rendered in a private dispute, was the following conclusion:

Community law and, more particularly, Article 6(1) of (…) Directive 2000/78/EC (…) must be interpreted as precluding a provision of domestic law such as that at issue in the main proceedings (…) It is the responsibility of the national court to guarantee the full effectiveness of the general principle of non-discrimination in respect of age, setting aside any provision of national law which may conflict with Community law, even where the period prescribed for transposition of that directive has not yet expired.

The judgment evoked a great amount of criticism from the media, academia, several advocates general and the member states.

Forms of res judicata – Unwritten principle of EU law – National procedural autonomy v. EC supremacy – Revision of decisions v. state liability – Finality of administrative decisions v. judicial decisions – Higher respect for judicial decisions than for administrative decisions – Res judicata not absolute – ECJ itself under demands of legal certainty – Analogy between res judicata rules and rules of direct and indirect effect.