This study sets out to examine the relationship between ideals and interests in the creation of the preferences of two right-wing populist parties regarding NATO-membership. The two parties who are examined are the Sweden Democrats and Danish People´s Party of Sweden and Denmark, respectively. The Sweden Democrats wish for Sweden to stay out of NATO, while The Danish People's Party wish for Denmark to remain in NATO, and this study sets out to discover the reasons for this difference of opinion between two right-wing populist parties. Such an analysis has not been performed previously in this way inside the broader study of right-wing populism, with the majority of academic study being devoted to, among other themes, the emergence of and subsequent voter demographics associated with right-wing populism.

The theory utilized for this investigation is "The Liberal Theory of International Politics" based on the works of Andrew Moravcsik, with the analytical indicators being ideals and interests, drawn from this theory. The design of this study is that of a comparative, small-n case study.

The findings show that there is a variation of ideals and interests between the two parties, with the ideal of peace being the most important for the Sweden Democrats, and the ideal of cooperation being the most important for the Danish People´s Party. National Security was the most important interest for both parties. The findings also showed that economic incentives had little impact on the shaping of either party´s preference when it came to the subject of NATO.