The book examines the changing approach of courts in reviewing foreign affairs decisions of the executive. Traditionally, the judiciary awarded deference to executive decisions in that area, a notion that clashes with the idea of general judicial oversight in the modern constitutional state. As the problem is often looked at solely from a national angle, this thesis chooses a comparative approach taking into account the development in three democratic countries to identify general trends as well as differences. Thereby, it shows the development of a new judicial approach, which does not per se defer to executive assessments in the field.