Drawing on qualitative investigations of three French cities, this this paper contributes to an understanding of the reasons behind the proliferation of activist city networks. Following the literature on the functions of transnational city networks, this article reveals four significant drivers that explain the preference of French cities for national city network ANVITA over international city networks amid a surge of welcoming initiatives. The four drivers offer opportunities to (1) share experience, (2) shame national authorities and propose alternative narratives, (3) limit pressure and opposition from NGOs and activists and (4) lend legitimacy to current policies and attain a label of “welcoming city” for Green and left-leaning municipal coalitions. Thus, if the practical and symbolic functions are standard with international city networks, the symbolic functions play a significant role; some are explicit (shaming), whereas other are more implicit (relations with NGOs and partisan positioning). This article insists on the need to consider the political dimension of city networking as a significant driver for municipal actors. This political dimension is key to understanding how cities can (or not) be prominent actors in the governance of migration in the years to come.