The aim of this contribution is to highlight the action of the ARC in Switzerland during World War I. The goal is to understand what was done, but also to think on why the ARC has invested so much in a country that was not at war. Secondly, it will highlight the relationship between the ARC and the ICRC. How did both entities work? Did they coexist without major connections, or was this relationship marked by cooperation or rivalry? Finally the goal of this paper is to show the importance that had this relationship for the shaping of a new Red Cross World at the end of the war and its consequences for the development of humanitarian action, IHL and human rights during the 20s and beyond.