John was born in Dordrecht, The Netherlands to biology teacher Willemien and bookbinder Willem (specialized in ancient books and bibles). He has a brother, engineer Ton, and, since 2009, has been married to UN war crimes investigator and human rights specialist Lina. He studied law at Erasmus University Rotterdam, European Union law at the Bruges College of Europe and human rights at the European Master’s Programme in Human Rights and Democratization in Venice. He holds a PhD in international law from the European University Institute in Florence.
Since finishing the PhD in 2009 John has combined a part-time appointment as a university lecturer in European human rights law at the University of Groningen with different positions in Dutch civil service. He worked as a senior EU affairs adviser and senior human rights law at the Ministries of Justice and the Interior, working mainly on EU human rights and rule of law-, and privacy issues. More recently he served as the head of unit of the Interior Ministry at the Dutch Permanent Representation to the EU, including during the Netherlands EU presidency in 2016. His interests range from general international law to international and European human rights law to EU law, and more recently, populism. John’s publications and book reviews have appeared, amongst others, in Common Market Law Review, European Law Journal, International and Comparative Law Quarterly and Netherlands International Law Review and in edited books published by, for example, Oxford University Press, Cambridge University Press and Hart Publishing.