In May 2016, an organisation of Western governments headquartered in Berlin, called the International Holocaust Remembrance Alliance (IHRA), adopted a definition of anti-Semitism that incorporates anti-Zionism. That definition has become the pre-eminent benchmark for identifying anti-Semitism by governments, public bodies and universities across the global North. Due to its conflation of anti-Semitism with anti-Zionism, the IHRA is also a flashpoint in the global struggle over Palestine/Israel. Despite the definition’s political importance, much remains unknown today by both supporters and opponents regarding its origins, not least because the IHRA’s archives remain closed, and many public documents have been taken offline. Some...