The frontier between "law" and "politics" is not always clear-cut. Although courts are allowed to function broadly, governments and parliaments can also make independent decisions. Tim Koopmans compares the way American, British, French and German law and politics handle different issues. For example, highly "political" subjects in one country may constitute legal issues in another. Koopmans considers case law in a range of issues, including human rights protection, federalism, separation of powers, and the impact of European and international law.