This article explores Western attempts to strengthen mechanisms of informal justice in Afghanistan. It traces the origins and evolvement of what the article terms an informal justice assemblage; the constellation of specific expert discourses, institutional practices and strategic considerations that made it possible and plausible that Western actors should promote and work with informal processes of justice. The article problematizes expert statements that posit that working with informal justice is somehow more Afghan-led and less of an outside imposition than to support the country’s formal justice system. On the contrary, it is detailed how- discursively and institutionally - academic authority about what is locally appropriate in practice served to foreclose national debate and scrutiny about the organization and administration of justice. This amounted to a net erosion of accountability, reinforced by the subsequent militarization of the justice sector and governance more broadly. In conclusion, the article calls for greater attention to the broader fields of power in which claims of sensitivity to local sentiments and reality in Afghanistan are made.