Questions of food sustainability cannot be limited to the national sphere, insofar as international interactions are undeniable. This chapter focuses on the ir role, concentrating on the volatility of global food priees and on public and private norms and standards. The international dimension of these questions is reflected first of all by questions concerning the volatility of agricultural priees. Although volatility itself is not the preserve of international markets, it has become difficult to address this issue without ta king account of the global dimension of agricultural markets, in terms of both the formation of priees and their subsequent adjustments. These issues have become particularly acute since the recent crises affecting food priees. When linked to the issue of food sustainability, they lead to questions on the types of adjustments made at a global leve! and the resulting differences according to the leve! of development of a country, as well as justifications for, and the modes of, public intervention. Commercial policies that are directly affected by international interactions play a particular role in this respect, and this merits discussion in order to analyse the challenges inherent in their application and any disciplines associated with their use. However, international interactions are not restricted to priees. Indeed, tracte affects the capacity of public and priva te agents to lay down and subsequently apply norms and standards, as well as the scope of their influence; in return, these norms and standards may exert a substantial effect on tracte. During the past 20 years, the rapid deveiopment of public and private norms and standards linked to sustainability issues has th us raised a series of questions on the reasons for them and their consequences in terms of international tracte.