I want to thank ASIL and Professor Jill Goldenziel, for inviting me to participate in today's panel.

Maybe it is too soon to call it a tradition, but in recent years your colleagues and friends in The Hague have sponsored this closing plenary with much pleasure. In cooperation with the City of The Hague and His Majesty's Embassy, the Asser Institute for International and European Law has organized the panel discussion at the closing plenary. Our subject this year is multilateralism, a topic that is close at heart to many of us. That is certainly the case for us, practitioners and scholars based in The Hague, where international efforts for multilateral agreements and institutions have been part of the fabric of our city since the nineteenth century. Multilateral institutions continue to define the spirit of our city.

The very notion of “multilateralism” seems straightforward. It immediately suggests an approach of international relations different from the one to which other “ism” notions refer, like “unilateralism,” “bilateralism,” “regionalism,” imperialism,” and “colonialism.” In this respect, “multilateralism” sounds like some kind of good international governance, like an alternative to the absence of a “global state.” Yet, in any endeavor to assess what could be “the future” of multilateralism, it is worth trying to better approach the notion, as it is understood in the international legal world.

The multilateralism that we practice at North Atlantic Treaty Organization (NATO) derives from the North Atlantic Treaty, also known as the Washington Treaty in honor of this city, where it was signed on April 4, 1949. Next year we will be celebrating seventy years of this remarkable document, which provides the legal foundation for NATO's continued adaptation to the changing transatlantic security environment. One recent example of this adaptation came last year when Montenegro joined the Alliance. Montenegro's accession received almost unanimous advice and consent in the Senate. That is an important sign of the continuing vitality of interest in multilateralism here in Washington.

Some twenty-five years ago, John Ruggie defined “multilateralism” in terms that remain apposite today. As an international lawyer, this definition prompts me to reflect on the connections between the international legal order and multilateralism. To be sure, international law has unilateral, bilateral, and multilateral features, for example in lawmaking or law enforcement. Similarly, it can be wielded to unilateral, bilateral, or multilateral ends. Indeed, it is precisely because it transcends ends and issue areas, that international law, by providing “generalized” principles of conduct and interaction, is an important component of multilateralism.

Multilateralism can be seen as the greatest source of legitimacy and inclusiveness in the international system. In thinking of multilateralism, I am inspired by Harlan Grant Cohen's Editorial Comment in the January 2018 issue of the American Journal of International Law, in which he explains that multilateralism is a process that is more inclusive than unilateralism or bilateralism. Following that definition, it would imply, for example, that cooperation activities at the United Nations (UN), with its membership of 193 States, are more a reflection of multilateralism than cooperation activities at the Organisation for Economic Co-operation and Development (OECD), with its membership of thirty-six states, or at the North Atlantic Treaty Organization (NATO), with its membership of twenty-nine states. But by the same token, efforts at multilateralism could be harder to achieve results, given that achieving consensus among 193 countries would be more challenging than doing so among a smaller number of countries. It would also stand to reason that regional or plurilateral arrangements are less reflective of multilateralism than are multilateral arrangements. But of course, multilateralism should not only be viewed against a yardstick of numbers, but also in terms of legitimacy, effectiveness and impact of activities and outputs.