The boomerang model is typically used to describe campaigns in which international NGOs respond to requests from local activists, often from marginalized populations, for assistance in addressing local needs. Such campaigns are perceived to represent local interests and have some accountability to local actors. However, while the local–international–local pattern is often accurate, it does not capture the full spectrum of campaign development. This article theorizes an international–local–international or ‘inverse’ boomerang, in which international NGOs facing an international policy blockage initiate a transnational campaign, recruiting local activists to assist in the international advocacy effort. The article demonstrates the theory's plausibility using several cases of Northern‐initiated advocacy. It then examines the implications of the model for campaign legitimacy. It finds that inverse boomerang campaigns benefit from the same presumptions of legitimacy as traditional boomerang campaigns, but that representivity and accountability are substantially weaker, potentially disempowering the campaigns' claimed stakeholders.