The conflicts in Iraq and Syria have led to concerns in the West over ‘foreign fighters’. Although states are anxious about the role these individuals play in the conflicts they join, their primary concern relates to the perceived ‘terrorist’ threat they pose on their return. This fear has led to an evolution in the international policymaking arena, with foreign fighters now often referred to as ‘foreign terrorist fighters’ (FTFs). A Critical Theory-inspired immanent critique is offered to highlight various problems that exist with the FTF term and to argue policymakers should resist its use. The article demonstrates the importance of language by showing how the invocation of the FTF threat has strengthened the ongoing development of globally coordinated counterterrorism action. Specifically, it argues UN Security Council Resolution 2178, agreed in 2014, generates a legal obligation upon UN member states to implement new counterterrorism laws at national level to combat the perceived threat from FTFs. The article highlights the negative effect these laws have on human rights. It is argued institutions like the UN need to ensure new counterterrorism legal instruments are built from a human rights rather than security-first perspective if commitments to human rights in transnational counterterrorism are to be fully realised.

The Syrian civil war has highlighted the phenomenon of foreign fighting, in which individuals leave their home State to join an armed conflict overseas. The predominant paradigm for regulating foreign fighting, centred on United Nations Security Council Resolution 2178, is based on counterterrorism, which in essence treats foreign fighting as a form of terrorism. This paradigm is largely reflective of the domestic legislation of the United Kingdom, United States, Canada and Australia. This article argues that this approach is problematic, and that an alternative paradigm based on the international law of neutrality and related domestic legislation provides a better means for regulating foreign fighting.