Defragmentation of Public International Law Through Interpretation: A Methodological Proposal

An expanding body of descriptive, explanatory, or aspirational literature has been written about the condition of public international law (PIL) today. De-formalization, fragmentation, and legal pluralism were the main topics of discussion. To restore unity and consistency to international law as they exist in national legal systems, European scholars frequently turn to constitutionalist theory to address these alleged issues. Most of the scholarship has been devoted to showing that there is a need for international constitutionalism or to describing that we can already diagnose global constitutionalism, often by taking a positivist or idealist view and mostly focusing on the interaction of international law and national law. These principles are largely consented to and positivized in international law. A discourse of justification is, while still needed, not as pressing as it once was. Rather, a discourse of application comes to the fore if the goal of unity and consistency for PIL is pursued, thus mitigating the dangers arising from different-and possibly conflicting-regimes. International courts and tribunals are proliferating' and adjudicating on issues that would be considered-were they not transnational or international in nature-constitutional problems. In national law, countervailing values, that is intra-constitutional conflicts, are reconciled through a balancing of those values, usually embedded in the application of the proportionality principle. A similar mechanism in PIL remains underdeveloped from a methodological point of view. This article aims to develop a methodological proposal for defragmentation through interpretation, drawing on legal theory.

Fragmentation and Constitutionalism

The link between WTO agreements and other areas of international law, including multilateral environmental agreements or international human rights law, is a hot topic of dispute. Even though they have received less attention lately, "investment" issues are still quite important. Even though international human rights legislation is frequently seen as leading constitutionalist arguments, the role of human rights in non-human rights concerns on the international scene is less established, at least when it comes to legal approach.

Constitution is traditionally associated with nation-states, even more so among German scholars. This is even reflected in the notions used (Verfassungsstaat, Rechtsstaat, Staatsvolk), which makes it more difficult for German scholars to imagine a constitution without a state and its demos. This historical understanding of constitution, with its restricting German terminology, is not used here. Instead, a functional approach is taken. Following others, we understand the term constitution in a normative sense as the sum of the basic and materially most important legal norms that comprehensively regulate the social and political life of a polity and usually have special impediments for modification. The norms do not have to be written down in one single document. They include the most basic values of a polity, as well as its institutional and procedural organization, and can be reformulated in decision theory terms as principles to be optimized. Constitutionalization denotes the process by which constitutional law comes into being, the emergence of constitutional law. There is broad consensus that international law has developed immensely since World War II.

Christian Tomuschat uses four steps to describe the evolution of international law: first, international law as a law of coexistence; second, international law as a law of cooperation; third, international law as a comprehensive guide for social life; and fourth, international law of the international community. Most scholars distinguish between the old law of coexistence, the interim law of cooperation, and the current process of constitutionalization.

By weighing those opposing principles, conflicts between the ideals and tenets of various PIL domains might be lessened. This facilitates the resolution of intra-constitutional disputes on a global scale.

Defragmentation through Interpretation

The primary rule of conflict in constitutionalized legal systems is the lex superior rule, which gives constitutional law precedence over other laws. A largely horizontally structured system remains, except for jus cogens (which does contain some human rights) and Article 103 of the U.N. Charter, unless one argues, for example, that human rights should always "trump" other international law—a claim that is difficult to substantiate.

There are many ways for international courts and tribunals to consider other PIL when adjudicating based on one special treaty. Choosing interpretation under Article 31(1) or interpretation under Article 31(3)(c) of the Vienna Convention ^[1]can be a difficult task. Nevertheless, any starting point for the interpretation of treaties is Articles 31 and 32 of the Vienna Convention. ° Article 31(1) states the general considerations in interpretation: (1) the ordinary meaning of the terms of the treaty, (2) the context, and (3) the treaty's object and purpose. It is widely accepted that the aim of treaty interpretation is to give effect to the intention of the parties. There is no consensus on whether there is a hierarchy in the arguments. It is often held, although disputed, that common law lawyers tend to stress the ordinary meaning, whereas civil law lawyers tend to stress the object and purpose as a teleological method. Reconsidering the debate on interpretative methods of Article 31 (1) is beyond the scope of this article.

As a "general concept of treaty interpretation, namely that of systemic integration within the international legal system," observers have interpreted Vienna Convention Article 31(3)(c) to have the "status of a constitutional provision within the system of international law. It performs a purpose like that of a master key in a big facility in this capacity. "Six Every international law norm must be construed in the context of other international law, including general international law, customary international law, and even other treaty norms. No international law standard may be regarded in isolation.

A Theory of Rational Balancing

The principle of proportionality serves as the most notable example of the balancing technique, which is mostly employed in constitutional law. Originating in German law, it permeated most worldwide legal frameworks and systems. According to the ruling of the Israeli Supreme Court, "proportionality is recognized today as a general principle of international law", it can therefore be considered a PIL meta-principle. It is widely used in all nations with constitutional review, as well as in international law (such as that which is implemented by the Appellate Body of the WTO and the European Court of Human Rights), even though it may have distinct names and specific applications.

Some Possible Implications

Investment law and trade law both contain potential conflicts with other areas of PIL. As mentioned before, those conflicts would be, were they not transnational, considered intra-constitutional conflicts. In the following Part, I will give some examples of these conflicts. It should be stressed that, whereas in trade law, some kind of balancing has been used and there is more extensive case law, especially through the necessity test in GATT Article XX, this method has been applied only rarely in investment law.^[2]

It is believed that other areas of special international law are not given enough consideration, which is why investment law is coming under growing criticism. Bilateral Investment Treaties (BITs) provide significant safeguards for foreign investors against political risks and, consequently, specific acts by their host countries, complying with public international law. What is a fair and balanced way for tribunals to interpret laws that are not investment related? To uphold their commitments under international or constitutional law pertaining to human rights, states may expressly adopt broad legislation.

Under Article 31(3)(c) of the Vienna Convention, those requirements also serve as opening windows for the consideration of human rights norms due to their highly ambiguous legal meanings. Tribunals may consider the goal of the regulatory measure in addition to the "sole effects" theory when considering indirect expropriation.

[1] . See e.g., RICHARD K. GARDINER, TREATY INTERPRETATION (2008); 1 OPPENHEIM'S INTERNATIONAL LAW, pts. 2-4, 1266-75 (Sir Jennings & Arthur Watts eds., 1995). Those rules of interpretation are accepted as customary international law.