The Principle of Good Faith and the Principle of Prohibition of Abuse of Rights

Abstract

The article analyzes the approach adopted by the International Court of Justice regarding the principles of good faith and the prohibition of abuse of rights, examining their structural function within the contemporary international legal system. It is argued that both principles fulfill a dual function: on the one hand, as guarantees of justice and equity among States; on the other, as mechanisms of institutional stabilization that enable the Court to modulate its jurisdictional intervention.
Furthermore, the study describes the origin of both principles, their doctrinal understanding, their positivization in the main international treaties, and their application in landmark cases such as Nuclear Tests (Australia v. France), Gabčíkovo–Nagymaros (Hungary v. Slovakia), Certain German Interests in Polish Upper Silesia, and Equatorial Guinea v. France. It is thus demonstrated that the ICJ makes expansive use of good faith to consolidate informal legal commitments, while it adopts a restrictive approach to the abuse of rights, since its invocation could affect access to international justice.
As a central contribution, it is concluded that these principles simultaneously operate as criteria for the functional limitation of sovereignty and as tools of judicial self-restraint. Nevertheless, their application remains under tension due to the absence of uniform objective standards, which poses significant challenges for international legal certainty.