In this article, we propose an initial comparative approach to the cultural and political impact of the First World War on Spain and Argentina, considering the common denominators and the singularities of both social experiences of the conflict. The relevance of the proposed comparison lies in several factors. In the first place, deep historical, cultural and demographic ties bound both nations. In second place, during the First World War, Spain and Argentina adopted a neutralist foreign policy, unaltered despite several diplomatic incidents with the warring nations, and of internal and external pressures. In both cases, civil society displayed a high level of political and cultural polarisation, and undertook an active mobilisation. Finally, there was a remarkable circulation of ideas and intellectuals through both margins of the Atlantic Ocean, which nourished the public controversies on the Great War. Nevertheless, beyond these similarities and confluences, there were also significant differences between Argentina and Spain, which exerted an influence on the countries position towards the conflict. The national cases analysed in this article demonstrate that diplomatic neutrality did not imply necessarily the indifference or passivity of civil society. Rediscovering neutrality within the war dynamics is one of the most stimulating paths for research.