The destruction of heritage in conflict has emerged as a key challenge to global security and the prospects of peace. In response to the deliberate targeting of heritage sites by the Islamic State (IS) and other actors in recent years, the international community has launched a number of initiatives designed to protect and reconstruct key heritage sites in complex (post-)conflict contexts. However, this article demonstrates that such initiatives are often underpinned by the norm that the protection of heritage in conflict can serve to enhance the prospects of reconciliation, stability and peace. This article problematizes this norm by focussing on the case study of Shia responses to the targeting of their religious heritage sites by the IS in Iraq from mid-2014. It documents the ways that key Shia leaders instrumentalized the case of protecting heritage not to advance peace and security, but to create entirely new militias, to recruit thousands of Shia faithful, to mobilize them to fight against the IS, and to engage in violence and human rights abuses. This raises significant concerns about whether the promotion of heritage as a pathway to peace could inadvertently exacerbate conflict and lead to renewed waves of violence and heritage destruction.