Standard of Review and the Margin of Appreciation before the International Court of Justice

The chapter addresses the question, which is still controversial, whether, as regards the International Court of Justice (ICJ), a doctrine of judicial deference to other bodies’ actions or to national decision-making exists, and what is the applicable standard. The analysis focuses on the practice of the Court in interstate disputes and is conducted with the view to establishing whether, especially with reference to norms leaving by themselves a margin of discretion to the state as to their implementation, the ICJ retains a power of review and, in this case, what standard (if any) may be inferred from its rulings. As regards this matter the chapter attempts to provide an answer to the question whether good faith can be regarded as a standard of review, like the jurisprudence of the Court seems to suggest, and how it has been applied (or should have been applied) according to the relevant practice; it then addresses the question whether, in situations where the ICJ has recognized or should have recognized a degree of discretion to the state as to the assessment of international law norms, this attitude could be regarded as amounting to judicial deference towards national decision-making and whether, in the case of a positive answer, the margin of appreciation doctrine may be applied.