Islamic International Humanitarian Law and the War Against ISIS in Iraq:

Competing Interpretations and Legal Applications

Mohamad Ghazi Janaby

Hayder Kadhim Al-Qurashi

 

Abstract: This note examines the practical applicability of Islamic legal and ethical principles to the armed conflict with the Islamic State in Iraq and Syria (ISIS) by offering a comparative analysis of their interpretation and deployment by opposing Islamic actors. It first explores how ISIS mobilised a radicalised doctrinal framework, centred on takfīr (act of declaring a Muslim to be a non-believer) and selective citations of Qurʾānic verses and prophetic traditions, to justify mass atrocities, including systematic violence against Shi’i Muslims and religious minorities. In stark contrast, the note analyses the response of the leading Shi’i religious authority, Grand Ayatollah Sayyid Ali al-Sistani, who issued a sufficiency-based fatwa and a set of humanitarian directives aimed at constraining the conduct of war through a normative framework grounded in Islamic jurisprudence. The note argues that al-Sistani’s intervention offered an ethical alternative to both the doctrinal extremism of ISIS and the limitations of existing international humanitarian law (IHL), particularly in the context of non-international armed conflicts (NIACs). Through this lens, the note contributes to broader discussions on the potential for Islamic law to complement and even advance humanitarian protections in contemporary conflicts.