As lawyers, texts are – to a large extent – our ‘stock in trade.’ And so, like many other lawyers, I have become fascinated by the ability of services such as ChatGPT to use large language models (‘LLMs’) to generate human-like text. Much has been written on how LLMs can pass bar exams and how they might affect various areas of national law. But there’s something of a blind spot when it comes to how LLMs will affect international law, particularly in the realm of treaty interpretation. Yet treaty interpretation, with its complex interplay of language, context, and legal principles, provides a particularly intriguing case study for the potential impact of LLMs.

Donna Lyons’s edited book, Leading Works on International Law, published at the end of 2023, has chapters by eleven authors describing works the editor had chosen as the leading works in international law published in recent times. The chapters on the works were written by the authors, making it an unusual collection in that each author was given an opportunity of stating how she or he came to write her or his work and what they considered to be the impact of their works. In a chapter titled ‘Battling Against Power: The International Law on Foreign Investment’, I was asked to describe the circumstances in which I wrote my book, The International Law on Foreign Investment (5th Edition, Cambridge University Press, London, 2021). In oriental traditions of scholarship, self-praise is to be avoided but it was, in this case, what I was required to do.