As recently evidenced by the Breivik killings in Norway and events in the Middle East, terrorism and civil conflict near and far are – perhaps more than ever – threats to human welfare in modern societies. Understanding how such incidents, which we label “threatening collective events”, influence human welfare and how the negative consequences can potentially be curbed remain key topics for the fields of social science and public health. The purpose of this project is to examine if, and subsequently, when and how, such threatening events in other countries influence individuals’ mental health in Denmark.