The International Health Regulations, last revised by Member States of the WHO in 2005, are the primary global agreement governing the international response to global health emergencies. The primary aim of the IHR, under Article 2, is to control the cross-border spread of disease in ways that “avoid unnecessary interference with international traffic and trade.” During the COVID-19 pandemic there has been widespread flouting of the IHR rules and the WHO advice, with the majority of countries imposing tough travel and trade restrictions that appear to be contrary to both the letter and the spirit of the IHR. At the same time, there has been emerging evidence to suggest that such restrictions at the border have – at least in some cases – played a part in helping control domestic outbreaks. This has led to a debate over whether the IHR 2005 and the WHO have the correct approach in their preference for borders remaining open, and whether the regulations should be revised in advance of future health emergencies. In this article, we argue that it is important that participants in these discussions remember why the IHR take the approach that they do. Much of the current debate focusses on the effectiveness of border controls in keeping disease out, and the supposed trade-offs between health security and the economy. Yet the human rights and international cooperation rationales for the WHO (and IHR) preferring open borders should not be forgotten. Drawing the lesson from COVID-19 that the WHO/IHR are wrong to warn against disease-related travel and trade restrictions risks forgetting the lessons of the past – and may set us up poorly for dealing with future disease emergencies.