While international law has typically waxed and waned in feminist favours, contemporary feminist engagements reveal a strongly critical, reflective thrust about the costs of engaging international law and the quality of ostensible gains. To inform this reflection, the article draws on feminist scholarship in international law – and a specific feminist campaign for the implementation of United Nations Security Council Resolution 1325 (2000) on Women, Peace and Security in Northern Ireland – to distill three distinct feminist understandings of international law that underpin both theory and advocacy. Firstly, international law is understood as a system of rules to which states are bound; secondly, as an avenue for the articulation of shared feminist values; and thirdly, as a political tool to advance feminist demands. The study finds that feminist doctrinalists, and those working within the institutions of international law, share concerns about the resolution’s legal deficiencies and the broader place of the Security Council within international lawmaking. These concerns are, however, largely remote for local feminist activists, who recognized in the resolution important political resources to support their mobilization, their alliances with others and ultimately, it is hoped, their engagement with state actors. The article concludes that critical reflection on feminist strategy in international law is usefully informed by more deliberate consideration of its legal, political and normative dimensions, as well as an awareness that these dimensions will be differently weighted by differently situated feminist actors.