It is a *cliché* for writers to end the acknowledgements sections of our books with the standard disclaimer, “Any errors that remain are solely the responsibility of the author.” And as true as that may be, I could add this corollary: “But this author is sure he would have many more errors in the text if not for the kind guidance of my dear friend Garbrielle Marceau.”

It has been my pleasure to know Gabrielle for the first quarter of this century, and a little of the last one, during which time she has helped this non-lawyer avoid many of the pitfalls that await any layman foolhardy enough to comment on the law. This was true above all for my World Trade Organisation (WTO) history,<fnref n="1" /> when she generously shared her time, experience, and wisdom. Many and varied elements in that book involved delicate questions of the law and diplomacy of intergovernmental organizations, and while every expert might have a distinct opinion there was only one who could be trusted to get it right always. I know I am not alone in that estimation, as I well recall a meeting with Director General Pascal Lamy to discuss a draft chapter. At one point he held up a page dealing with an especially nettlesome issue, and he asked if I was sure about what I had written. I told him I had cleared the language with Gabrielle. “Ah!” he said, as he exchanged knowing and confident looks with Chef de Cabinet Arancha Gonzalez. “If Gabrielle says so,” he assured me with a smile, “that settles it.”

The range of issues on which I have sought Gabrielle’s counsel over the years is too wide to recall, much less to recount. But if I had to identify the most significant theme it would be the many ways that the laws that are devised and adjudicated in one body may influence the actions and determinations in another. Her journal articles on the conflicts of jurisdiction between the WTO and other trade agreements,<fnref n="2" /> and especially in the field of human rights,<fnref n="3" /> are required reading for anyone who wants to understand the many ways that issues are no longer sequestered in distinct institutions and agreements.

While Gabrielle’s writings are a matter of public record, not everyone will know how indispensable she was to an executive education course on trade that we taught annually at the Harvard Kennedy School from 2001 to 2022. The videoconferences that have become such a mainstay of our work in the last several years were still a great novelty when my colleague Robert Lawrence and I first began teaching this course, and I will be forever grateful that Gabrielle agreed to join us through that medium in our first year—and in every year to follow. She was not only the sole guest to take up this invitation throughout the years, but her question-and-answer sessions were always a highlight. When participants graded the program and the professors at the end of each course they invariably let us know how thoroughly she helped to overcome the gap between what one can study in the classroom and what one can truly learn from a consummate professional.

It is with mixed feelings that I heard of Gabrielle’s impending retirement from the WTO. While it does mean that I can no longer make my stop by her office one of the more obligatory and pleasant parts of any visit to Geneva, it also means that she should have more time to expand her contributions to the literature. I look forward to seeing what comes of it.

I can attest that all the above is true, without holding Gabrielle responsible for its veracity. Any errors that remain are solely the responsibility of the author.

<footnote n="1">Craig VanGrasstek, *The History and Future of the World Trade Organization* (Geneva: World Trade Organization, 2013).</footnote>

<footnote n="2">Kyung Kwak and Gabrielle Marceau, “Overlaps and Conflicts of Jurisdiction between the World Trade Organization and Regional Trade Agreements” (2004) 41 Can YB Intl Law 83.</footnote>

<footnote n="3">Gabrielle Marceau, “WTO Dispute Settlement and Human Rights” (2002) 13:4 EJIL 753.</footnote>