He has performed at organ concerts in Germany and at Notre Dame de Paris, Jerusalem, New York City, Singapore and Kraków.
[2] According to a critical review of the book by Gunter Hofmann,[3] the book is centered on the necessity of the state to defend itself in a "global civil war" in the "age of terrorism", and refers to the U.S.'s Guantanamo Bay detention camp as a "legally permissible response in the fight of constitutional civilisation against the barbarity of terrorism".
Depenheuer's critics accuse him of promoting the anti-liberal thought of authoritarian theorist Carl Schmitt, who is liberally cited in the book, and of perceiving terrorism as a faceless evil to which state-organised violence is the sole appropriate response.
[3] In his defence, Depenheuer stated in an interview that "enemy and victim are fundamental categories of politics" and referred to "some of the constitution's numerous exegetes", who disagree with him, as a "security risk".
[4] Since 2015, Depenheuer is workstream leader for the AMU (Agency for the Modernisation of Ukraine), where he contributes his expertise in law.