What is a reasonable understanding of different forms of justification and to what extent arethese applicable to the processes leading up to political decisions? In what ways are the nature of political decisions of relevance for justification, and what role could morality play in the shaping of these political decisions, in particular in relation to the reasons provided as argument regarding engagement in peacebuilding in states’ foreign policy? In order to address these questions this article makes use of the concepts of justification and to some extent legitimation of political decisions and action. In particular, it discusses a distinction between pragmatic, moral and ethical justification, and legitimation. It is argued that pragmatic justification implies a political or strategic approach towards the decision that is to be justified,while moral justification concerns the rightness or wrongness about the reasons for the political decisions. Ethical justification, on the other hand, concerns the principles governing the decisions. In this article, it is argued that these need to be understood on different levels.The position argued for in the article is based on a Kantian approach towards justification of political decisions, and builds on reasoning by Immanuel Kant, Jürgen Habermas and Rainer Forst. This assists putting an emphasis on the role of humans as rational beings, as well as the principles governing the arguments used for taking decisions on getting involved in peacebuilding. Based on the reasoning throughout the article, I defend an understanding where arguments for political decisions in foreign policy primarily should be understood asattempts toward pragmatic and moral justification.