Spillover terrorism? Exploring the effects of the Israel-Hamas war on jihadist violence in Europe

Several scholars have examined the impact of critical events in international politics, such as the Syrian civil war, on transnational violent extremism and terrorism. The same complex question arose following the war that broke out between Hamas and Israel on 7 October 2023. Building on original data on attacks, this article aims to examine the effects of this war in the Middle East on terrorist violence inspired by global jihadism in Europe, in the interplay among individual, organizational/group, and societal factors. The original attack data show that the Israel-Hamas war contributed to increasing the frequency of attacks carried out in Europe and led to a growth in the number of attacks against Jewish and Israeli targets; however, it did not have profound effects on the level of organization and the severity of these acts of violence. Taking this empirical evidence into account, the article argues that this armed conflict was generally able to indirectly affect, from a distance, the intentions of European-based sympathizers and militants to mobilize but, unlike other wars in the past, it did not provide them with direct opportunities to join major organizations and to increase their capabilities in the use of violence.