The legal dimension of backlash against International organizations. Countermeasures and the principle of cooperation

The chapter explores member States’ measures against international organizations (IOs) through the lens of current international law and practice, with a view to shedding light on the tensions and uncertainties that such law and practice generate. The chapter focuses on the legal nature of the measures taken by member States against IOs, and particularly on their qualification and possible justification under international law. It provides, first, a selection of recent cases that might help in understanding the multifaceted character of this practice and a possible categorization of measures of contestation against IOs. Secondly, the chapter takes stock of the way these measures have been analysed so far, focusing in particular on the solutions provided by the International Law Commission (ILC). Finally, the chapter centres on the principle of cooperation between IOs and its members that inspired the ILC in this field and questions its relevance for the legal characterization of such measures under international law.