Abstract
In the past 20 years, student movements, environmental movements, women's movements and peace movements developed both in America and in Europe. These actions meant an explosive growth in the number of publications about social movements. Theory formation took a different course in Europe and in the U.S. While in the U.S. resource mobilization theory shifted attention from deprivation to the availability of resources in explanation of the rise of social movements, in Europe the “new social movement approach” emphasized the development of postindustrial society. Resource mobilisation and the new social movement approach are discussed. Both approaches are needed to arrive at a satisfactory explanation. The new social movement approach has concentrated on factors that determine mobilization potential, but does not give an answer to the question of how these potentials are mobilized, Resource mobilization theory does pay attention to the mobilization of resources, to the significance of recruitment networks, and to the costs and benefits of participation, but has no interest in the mobilization potentials from which a movement must draw in mobilization campaigns. Assumptions are formulated in explanation of the divergent development of the social movement literature on the two continents.