This article studies a UK Court of Appeal decision, in which the judges had to interpret the definition of the crime of terrorism provided in the UK’s Terrorism Act. In particular, they had to decide whether violent attacks by non-state armed groups against state armed forces, perpetrated in the context of a non-international armed conflict, qualify as acts of terrorism under the UK’s legislation. The defendant in this case had filmed and posted videos of such attacks and was charged with dissemination of a terrorist publication.

The article critically examines the methodology adopted by the Court of Appeal, its interpretation of the domestic notion of terrorism, and its over-reliance on the so-called Lotus principle. It also reflects critically on the Court of Appeal’s position on the relationship between the UK’s domestic legislation and the current international legal framework on terrorism.

In particular, the defendant argued that, based on international law, in situations of a non-international armed conflict, attacks by non-state armed groups against governmental armed forces could be exempted from being labelled as terrorist acts. The Court disagreed by asserting a distinction between attacks carried out against state forces in international armed conflicts (e.g. those committed against the Israeli forces in Gaza), and attacks perpetrated during non-international armed conflicts): while the former were not considered acts of terrorism, the latter were. According to the law applicable to such conflicts, the Court observed that members of non-state armed groups are not shielded by any combatant immunity. Thus, acts committed by such members remain subject to domestic criminal law.

This article contests that assumption. International conventions on terrorism binding on the UK establish that all attacks committed in the context of an armed conflict – whether international or non-international – are to be governed by international humanitarian law (IHL). The Court should thus have interpreted the UK’s domestic legislation consistent with the IHL definition of terrorism. Marking actors as terrorists, even when they abide by the laws of war, constitutes a disincentive to comply with humanitarian laws. Finally, this article is relevant to the situation in Southeast Turkey, since it sets the legal framework applicable to cases of terrorism during a non-international armed conflict.

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