The history of peace research offers a window onto mid-twentieth-century European political thought in transformation. This chapter focuses on the transformation of peace research from the 1960s to the 1980s, as it evolved a radical and trans-national approach to politics, linking developmentalist concerns with decolonisation and economic underdevelopment at the global scale to a critique of social hierarchies at the national scale. Historically located both after the post-war pursuit of European peace through economic growth and regional integration and before the emergence of Euromissile peace movements of the 1980s, one strand of peace research soon became an approach to social justice all of its own, and came to be known as ‘positive peace’. Positive peace was most prominent in the Nordic countries, where it offered a means of connecting nationally framed accounts of social democracy to more radical and utopian calls for social justice on all political scales. During these years of international encroachment and domestic upheaval in Europe, positive visions for peace provided a space within which European intellectuals responded to newly recognised global-scale injustices such as the Vietnam War and the spectre of global famine, as well as building a more just social order at home.