The work of legal practitioners in the field of international law, particularly when working in a ministry of foreign affairs, takes place at the crossroads of international relations and international law. The legal advisers of ministries of foreign affairs provide advice on the content of international law, and how it should be interpreted and applied in a particular situation. Since Johan Lammers became Legal Adviser, the Netherlands - quite unexpectedly - was increasingly facing situations in which it would become involved in litigation concerning international law. The first essays in this collection deal with actual or potential interstate disputes involving the Netherlands before international courts and arbitral tribunals, followed by articles with respect to international courts and other international bodies before which individuals may appear as applicant or defendant. The final set of essays deal with the increasing number of cases in which international law is invoked in national court proceedings. This work provides insight into the role of the international legal practitioners working for the government of the Netherlands and should be of particular interest to their colleagues in other foreign ministries and other lawyers interested in a reflection on the law in action.