US-led political reconstruction in Afghanistan--namely the introduction of a constitutional democracy and the establishment of a multi-ethnic state--has led to the politicization of ethnicity in national politics. Despite this, the literature on identity in Afghanistan remains silent not only on impacts of this politicization in everyday life, but also on the functioning of contemporary ethnicity, more generally. As such, this paper explores the impacts of post-2001 political reconstruction upon ethnicity and interethnic relations in the Bamyan Valley. Methodologically, this is achieved by drawing on Afghan scholarly literature relating to identity and ethnographic research conducted in Bamyan from 2010-12. The paper also applies a progressive constructionist theorization of ethnicity--Rogers Brubaker's conceptualization of ethnicity as operating through 'categories' not 'groups'--to the Afghan context. Such a framing of ethnicity allows for the scope of inquiry to be expanded: moving beyond analysis of ethno-nationalist politics to that of everyday experience. Utilizing this approach, the paper draws on two case studies; one investigating Iranian-sponsored promotion of Ashura and associated Shi'i mourning rituals, and another exploring violence and changing interethnic marriage patterns in Bamyan. These cases demonstrate the use of ethnic identity for political ends and illustrate changing relations between Bamyani Hazarahs, Tajiks and Saadat. The paper concludes that political reconstruction in Afghanistan has resulted in major shifts in the control of productive resources (i.e. political appointments, access to health and education services, and control of land, the marketplace and trade) in Bamyan. As a result, Hazarahs are benefiting from improved status and shifting power relations. This shift, in turn, is manifest in changing interethnic relations including the utilization of Ashura to promote sectarian sentiment and tensions between Hazarahs and Tajiks. And, increasing elopement and retaliatory violence as contestation of ethnic identity between Hazarahs and Saadat. More broadly, these conclusions contribute to a more detailed understanding of the impacts of political reconstruction in Afghanistan and talk to prospects of national integration. They also indicate entry points for mitigating patterns of interethnic violence and outline insights for peacebuilding policy.