Before being appointed Ambassador to the Netherlands in 2016, Ambassador Brengelmann served as Special Representative for Cyber Foreign Policy at the Federal Foreign Office and then as Germany’s Ambassador to Brazil. From 2010 to 2013 he was NATO’s Assistant Secretary General for Political Affairs and Security Policy, where he advised the Secretary General on political issues, including NATO’s partnership relations and interaction with other international organizations.

Ambassador Brengelmann joined the German Foreign Service in 1984. He served as Deputy Chief of Mission at the German Embassy in Port-au-Prince and as Political Counsellor at the German Embassy in London, Deputy European Correspondent in the Federal Foreign Office, and Political Counsellor at the German Embassy in Washington DC. From 2000 to 2003 he was Deputy Director of the Cabinet of NATO Secretary-General George Robertson.

Since his retirement in July 2021 he has taught Political Science at the University of Bonn; in March 2023 he became Dean of the Global Diplomacy Lab in Berlin.

Ambassador Brengelmann has been an ICMP Commissioner since May 2019.