Balancing justice and long-term peace and security in a postconflict context is highly complex. This article discusses the challenges in Iraq’s post-IS (Islamic State) landscape. Based on a review of relevant Arabic, English and Persian academic scholarship on Islamic law and Islamic political science on accountability and transitional justice, it discusses what Islamic law dictates state authorities to do with detained suspects of atrocity crimes and terrorism and explores possibilities in Islamic law to balance justice and long-term peace and security. The article concludes that crimes against the state should, according to Islamic law, in principle lead to harsh punishments. However, that same body of law also provides for opportunities to adopt non-retributive alternatives, if this allows government to more swiftly handle the security crisis, re-establish public harmony and prevent further bloodshed in the future. The popular perception of the Iraqi people supporting retributive approaches could however pose an important barrier that could block any changes to Iraq’s current transitional justice approach.