Persistent Tensions? International Legal Perspectives on ‘Other’ Foreign Fighters

This paper takes as its starting point the question of whether and to what extent States may have an international legal obligation towards other States to seek to prevent those within their jurisdiction from travelling abroad to fight with a non-State armed group in a foreign armed conflict. While there is a strong basis for such due diligence obligations regarding the prevention of terrorist activity, including Security Council Resolution 2178 (2014) on ‘foreign terrorist fighters’, the scope of responsibility is less clear regarding broader categories of foreigners participating in civil war, despite a long history of foreign volunteers in armed conflict. In this paper, I present a reading of two possible resolutions in international law to the question posed by this ‘other’ foreign fighting and explore the tensions between them. The first is based on State responsibility, sovereign equality, and diligent prevention of harm; the second on a more contextual reading of human rights considerations and global justice. The tensions surrounding ‘other’ foreign fighters provide a practical example of the oscillation between a reliance on the consent of States and a notion of the collective good in international legal argument. Acknowledging the practical reliance of States on these interlacing perspectives in different times and contexts, I suggest the importance of stepping back and slowing down to look beyond today’s predominant but narrower and rushed, focus on counter-terrorism approaches to take account of the key themes that have shaped the legal discourse and practice regarding a broader historical range of foreign volunteering in armed conflict