Public international law today plays a large and growing role in the decision-making of multinational companies with respect to their investments worldwide. Controversies between investors and states have increased in their complexity and importance.


The Traditional Paradigm of Public International Law: States vs. States

Traditionally, public international law has been concerned with the mutual rights and obligations of States vis-à-vis each other.

  • A key source of public international law are therefore conventions (also referred to as treaties) between States (bilateral conventions, if between two States; multilateral conventions, if between more than two States).
  • Additionally, for hundreds of years, certain fundamental rules have been considered to form part of public international law even in the absence of a treaty recording them in writing. This part of public international law is referred to as customary public international law. The existence of customary public international law is as such undisputed (and also referred to in, e.g., Article 38(1)(b) of the Statute of the International Court of Justice). But whether or not any given rule actually forms part of public international law can be heavily contested, including in international economic law.


The Evolution of Public International Law 

The State-centric concept of public international law has increasingly been challenged. The process began gradually.

  • In 1815, the world’s first intergovernmental organisation, the Central Commission for Navigation on the Rhine (CCNR) was created. Since then, and particularly as a result of post-WW II reconstruction efforts, a large number of intergovernmental organisations has been created. Intergovernmental organisations operate in a specific legal environment, largely independent of the legal order of nation states. As to the European Communities (now the European Union), it is rooted in supranational law, which is, again, different from both, traditional nation-state paradigms, on the one hand, and the law of classical intergovernmental organisations, on the other.
  • In the aftermath of WW II, the individual has entered the scene as an actor and legal subject in public international law, as evidenced by, inter alia, the 1950 European Convention on Human Rights and Basic Liberties (ECHR), and the 1951 Geneva Refugees Convention.
  • With the advent of globalisation, international economic relations have intensified, including between the developed world and emerging and developing markets. To facilitate German foreign direct investment in Pakistan, the world’s first Bilateral Investment Treaty, providing for investor-state arbitration in case of disagreements between investors and the host country, was entered into in 1957. Today, there are more than 2700 BITs, and a large body of arbitral case law has evolved, shaping the public international law of the twenty-first century.


The Relationship Between Public International Law and Domestic Law

There is no straight answer to the question on how the relationship between public international law, on the one hand, and domestic law, on the other hand, must be characterised.
Put simply:

    • Some countries have adopted the so-called “monist approach”, whereby there is only one body of law, encompassing both, public international law and domestic law. Parties will then principally be able to invoke public international law before national courts without great difficulties (although whether a given treaty confers individual actionable rights will always remain subject to case-by-case analysis).
    • Other countries apply the so-called “dualist approach”, whereby public international law and domestic law are two distinct legal orders. In the absence of national legislation transforming an international treaty into domestic law, the treaty will not as such be considered to confer actionable rights upon individuals or businesses. This said, certain mandatory principles of public international law may apply regardless of transformation, depending on the relevant country, and/or on the issues at stake.

Relevant Experience of BODENHEIMER Attorneys

Axel Benjamin Herzberg and Dr Rouven F Bodenheimer routinely advise both, investors and governments on international investment law issues. Mr Herzberg also handled a number of ISDS cases as Deputy Counsel at the Secretariat of the ICC International Court of Arbitration in Paris.

Dr Nicolas Klein worked for German Federal Constitutional Court Justice Professor Dr Andreas Paulus, himself a renowned public international law specialist who represented Germany, inter alia, before the International Court of Justice in the LaGrand case against the United States. Both, Dr Klein’s doctoral thesis and his LL.M. studies at Columbia University (New York) revolved around issues of international investment law, in particular the scope of application ratione personae of bilateral investment treaties.