The aim of this study is to examine upper secondary students' (n = 96) argumentation skills and ability to discuss a controversial issue: the evacuation of Finnish children to Sweden and other Nordic countries because of the war. According to their essays written on the basis of multifaceted and contradictory sources, most of the students were not able to construct arguments. Instead, they developed their own justifications. These findings suggest that a controversial issue enables discussions about emotional and ethical questions. Furthermore, a controversy offers an opportunity to raise students' awareness about the importance of source evaluation and valid argumentation.