Iran and Its proxies: attribution and state responsibility

Iran has invested heavily in proxy militias since the regime's founding in 1979. In the decades that followed, groups such as Hezbollah in Lebanon, Shi'a militias in Iraq and Syria, and the Houthis in Yemen have projected Iran's influence across the region. Today, Iran's proxy network is considerably weakened due to Israel's military actions following October 7, 2023, and the fall of the Assad regime in Syria. Yet the Houthis' attacks on Israel and against Red Sea shipping demonstrate how Iran's support to these groups continues to facilitate their conduct in violation of international law. This article examines Iran's potential responsibility for acts on the part of its proxies that violate its international legal obligations. It assesses first the grounds on which the proxies' acts could be attributable to Iran before addressing Iran's potential responsibility for aiding and assisting its proxies' harmful conduct. Finally, the article considers Iran's potential breach of primary norms of international law, such as the prohibition on the use of force, through its support to the proxy groups. The analysis highlights the varied relationships between Iran and its proxies and the difficulties that arise when seeking to hold Iran to account. Many of the proxy groups act with a degree of independence that precludes the attribution of their conduct to Iran. Other States might therefore be better served by calling Tehran out for its violation of primary norms of international law, including Common Article 1 to the Geneva Conventions.