This chapter explores the debates over the meanings of co-operation in the ICA and its members during the inter-war period, tracing their evolution from the end of the First World War throughout the 1920s and 1930s, as the ICA struggled to respond to economic and political challenges of the Great Depression and its aftermath. While many members staunchly defended the principle of co-operative neutrality against those who would align the movement with left or right, the crisis also highlighted the need for the co-operative movement to develop its own ideology and programme, especially if co-operation were to realise its idealistic ambitions to defend peace and democracy. The chapter examines how the ICA responded to the challenges of Bolshevism and Nazism, and considers especially the role of representatives of the Nordic countries, not only in defending political neutrality, but also shaping an idealistic vision of co-operation, based on the legacy of the Rochdale Pioneers.