The international community has experimented with a variety of tools for promoting the rule of law in weak states, yet with few successes. An innovative tool is hybrid commissions not supplanting the justice system of the target state but fighting impunity from within it. In this contribution I therefore seek to identify the factors that render this novel mechanism of rule of law promotion effective, arguing that a set of factors – support from the Attorney-General, civil society and powerful donors; as well as the commission’s institutional design, its strategy, and the personality of the commissioner – will determine if the changes initiated by the hybrid lead to a deeper transformation of the host state, or if there will be a rule of law rollback as soon as the commission leaves the country.

Scholarship on Transnational Advocacy Networks (TANs) increasingly recognizes that even weak states targeted by TANs may respond, and subvert, transnational norm socialization campaigns. It examines both the conditions conducive to such responses and the range of policy instruments available to these states. Yet this emerging work lacks a robust, contextualized account for how states devise the strategy and the content of their responses. This article builds on the policy-learning literature to elucidate the process through which states construct their antiTAN approaches. It suggests that states’ policy paradigms in the field of domestic security largely shape those responses, with different paradigms offering distinct priorities and instruments. The comparison of the divergent impact of the Guatemalan state’s contrasting responses to two similar legal-political challenges, undertaken in the context of the same anticorruption TAN campaign, illustrates the argument.