Combining new quantitative and qualitative data, this article first describes and compares the evolution of right-wing terrorism and militancy in the Nordic countries between 1990 and 2015. Having established that Sweden has experienced considerably more right-wing terrorism and militancy than the other Nordic countries have, the article then seeks to account for Sweden’s outlier position. In doing so, the article draws on three concepts proposed by social movement research: organizational resources, political opportunities, and frame analysis. Applying these concepts to the Nordic countries, the study finds that Sweden’s outlier position may result from different WWII experiences, leaving Sweden with a stronger and more resilient extreme right movement, but also from receiving more immigrants while lacking influential anti-immigration (radical right) parties, and from conducting a more restrictive public debate on immigration, leaving little room for anti-immigration concerns in the public sphere. While the first two explanations are consistent with existing research, the third challenges the dominant view on how the public debate on immigration might influence extreme right mobilization and violence.