This article considers the legal status of the prohibition on gender-based violence against women. The Convention on the Elimination of All Forms of Discrimination against Women (CEDAW) does not contain a prohibition on violence against women as such. However, the CEDAW Committee found in its General Recommendation 19 that the definition of discrimination against women in Article 1 CEDAW includes gender-based violence against women. As general recommendations are not binding, it is often suggested that, aside from the regional treaties on the issue, the prohibition exists only under soft law. By contrast, this article argues that the prohibition exists also under hard law. Whether the definition of discrimination against women in Article 1 CEDAW includes gender-based violence against women is a question of treaty interpretation.
The article contends that, in line with Article 31(3)(b) of the Vienna Convention on the Law of Treaties, the subsequent practice of States Parties in the application of CEDAW has established their agreement that discrimination against women in Article 1 includes gender-based violence against women. It argues further that General Recommendation 19 served as the catalyst for this subsequent State practice. The article also explores the relationship between treaties and customary international law and contends that CEDAW has generated rules of customary international law, namely that gender-based violence against women is prohibited and that there is an obligation on States to exercise due diligence to eliminate it. The large number of States Parties to CEDAW has not proved an obstacle to the generation of these customary rules.