The traditional treaty, conceived of as a contract between states, is in decline. Recent climate change negotiations have produced nonbinding instruments such as the Copenhagen and Cancun Accords; the financial crisis prompted governments to negotiate Basel III, a nonbinding framework for global banking regulation; the nonbinding Organisation for Economic Cooperation and Development’s Guidelines for Multinational Enterprises are developed countries’ primary rules governing the conduct of transnational businesses. Clouds loom on the horizon even in those areas in which the treaty’s prominence continues, such as investment and trade law. The World Trade Organization (WTO) has not reached a major agreement among its members since its founding twenty years ago, and some states have withdrawn from bilateral investment treaties or the Convention on the Settlement of Investment Disputes Between States and National of Other States (better known as the ICSID Convention).

Legal rules come and go. Methods of producing law may also flow and ebb. The authors of the call for papers in connection with this online Agora suggest that there is possible evidence that treaty as a method of producing international law is ebbing, and may be dying. I see no such evidence at present; rather, I argue here that the dying source of international law is not treaty but custom. In the more distant future, however, treaty, too, may become obsolete or at least less salient.

There are four categories of tools of international social cooperation: (i) international law produced through treaty (referred to herein simply as treaty); (ii) international law produced through custom, known as customary international law (CIL); (iii) international law produced through international organization decision-making (international legislation); and (iv) non-legal cooperative institutions (soft law). One of the signal characteristics of treaty is that no state is bound that has not explicitly and specifically consented. In order to sharpen the difference between treaty and international legislation, let us focus on international legislation produced by majority voting, which today is rare outside the European Union, but which may bind states without their specific consent.

As treaties decline, customary international law can be an important mechanism of international cooperation over the medium term. There are increasingly fewer treaties ratified by the United States, with a record-low number of five in 2009–2012, and fewer multilateral treaties adopted worldwide. Yet, the demand for global rules and standards has not abated. Thus, for many international questions where treaties are not available as a source of new rules, customary international law may serve as an interchangeable instrument of national policy.

When the United States terminated its seven-year occupation of Japan in 1954, it did so having signed a peace treaty. By contrast, the United States tried, unsuccessfully, to persuade Hamid Karzai to sign a Bilateral Security Agreement to accompany the drawdown of U.S. forces in Afghanistan. Even if Karzai had agreed to sign, the draft agreement bears much stronger resemblance to an alliance than to a peace treaty; it does not reference hostilities between the United States and Afghanistan, nor does it include any version of the term “peace treaty.”

The Arctic was one of the main theatres for strategic military confrontation during the Cold War between the blocs led by the United States and the Soviet Union. There was no place for multilateral cooperation, other than for very limited issue areas, such as the 1973 Agreement on Conservation of Polar Bears between the five states with polar bear populations. Yet, the warming of relations by the end of the Cold War changed all this. Inspired by Secretary-General Mikhail Gorbachev’s speech in 1987, in which the Soviet leader pro-posed various possible areas for Arctic cooperation, differing ideas for international cooperation were advanced. Canadians, in particular, were trying to advance international treaty-based general cooperation for the Arctic, but this never came to pass and it was eventually Finland who was able to broker soft-law collaboration between the Cold War rivals.

The title of this Agora and the first question it poses both ask whether treaties are in decline. With respect to multilateral treaties to which the United States is a party, the answer is a clear yes.

According to the U.S. State Department’s Treaties in Force database, the United States became a party to a record number of 105 multilateral treaties between 1990 and 1999. As set forth in Graph A below, during the period 2000–2009, the number of multilateral treaties the United States joined dropped to just 62, the lowest number since the 1960s. The preliminary data from the first part of this decade beginning in 2010 suggests that this downward trend continues, but it is still too early in the decade to draw any definitive conclusions.

We shouldn’t necessarily be concerned when international lawmaking is a victim of its own success. A trend in a given domain of international governance in which multilateral treaty-making gives way to bilateral and non-binding alternatives does not itself signal a decline in the influence or efficacy of international law. It may in fact be a normal symptom of a properly functioning international legal framework—as much a cause for celebration among international lawyers as for concern.

I wish to offer some brief reflections on this Agora theme, The End of Treaties?, from the perspective of a lawyer responsible for engineering international cooperation. I say “engineering” because international lawyers in this role must carefully weigh design tradeoffs in selecting among potential cooperative mechanisms, not unlike an engineer weighing the tradeoffs between materials in designing to a performance and cost specification. Like architects, international lawyers must also be attuned to the social dimensions of the arrangements they craft, but should ultimately privilege function above the aesthetics of legal form. Ugly international cooperative arrangements may nevertheless perform beautifully.

International law is going through a period of change and, potentially, expansion. At a point in history during the past millennium, the main sources of inter-State law were custom and general principles of law recognized by civilized nations. This came to an end with the Westphalian era when an international order slowly began to establish and a treaty system was developed. Thus, such international law sources as custom and general principles of law gave way to an era of treaties: carefully designed instruments at the international level that codified every single aspect of agreements and transactions between nations. This phenomenon was not exclusive to the universal level; it also took place at a regional scale during the twentieth century, which saw the emergence of regional organizations and agreements that would enable the development of a reasonably stable international or regional society.

This piece is adapted from an address delivered to a conference sponsored by the Council of Europe and PluriCourts on The Long-Term Future of the European Court of Human Rights in Oslo, Norway on April 7, 2014.

This post addresses the successes and challenges for the European Court of Human Rights (ECtHR), as seen from the outside. It draws upon my co-authored research on human rights systems outside of Europe to explain how these systems have responded to some of the same challenges now facing the Council of Europe and the ECtHR. My main contention is that international human rights courts, wherever they are located, require sustained political and material support if they are to thrive and grow over time.