International economic sanctions represent, in theory, the main legal and economic instruments for correcting the behaviour of states in the international environment. How these sanctions come to have effects depends on a rather delicate mix of legal rules, economic interests, and geopolitical context – a combination that rarely remains stable. To capture this reality, the article starts from several case studies from trade, the financial sector, and energy. From them, it is quite clear that once sanctions are introduced, the adaptation process begins immediately: the targeted actors, as well as those around them, find ways to shift trade routes, change financial instruments, or use opaque networks that make the rules harder to enforce. These examples show that, beyond the legal architecture, there is an economy of avoidance that operates according to its own logic. Part of the analysis focuses on secondary sanctions, a type of measure that changes the usual dynamics of sanctions quite a bit. In practice, they affect not only the sanctioned state or actor, but also those who come into contact with it and contribute – intentionally or accidentally – to avoiding restrictions. Even if, economically, such instruments sometimes produce results, from an international law perspective, things become more complicated. The issue of extraterritoriality and the way in which states’ powers are affected remains difficult. The conclusion proposes a fairly simple observation: if secondary sanctions are continued to be insisted on, legal tensions will not disappear. Hence, the idea that, sooner or later, other mechanisms will have to be sought that more clearly respect the international legal framework and avoid the conflicts that this type of measure continues to generate.
