The Constitutional Law of External Security: Military Operations in the Face of New Threats (funded by DFG)
Project start date (tentative): October 2026
Responsible:
Christian Marxsen & Alexander Wentker
About the Project:
Germany’s and Europe’s external relations are undergoing radical change. This research project addresses key aspects of this transformed environment. It analyses the constitutional framework governing new forms of military operations and seeks to identify and consolidate the relevant constitutional principles in the field of external security.
Changing threats and the proclaimed Zeitenwende in security policy are shifting and expanding the ways in which the Bundeswehr is deployed. The project examines how existing constitutional rules on defence and the armed forces can be applied to new forms of military deployment, such as military responses to so-called hybrid threats, including threats posed to critical infrastructure by ‘shadow fleets’ or unmanned drones, as well as the permanent stationing of Bundeswehr troops abroad. All forms of deployment are also increasingly shaped by technological developments. The project investigates how the constitutional framework governing the deployment of the Bundeswehr applies where new technologies are used. Artificial intelligence in the deployment of military force has so far received little constitutional-law attention. It does, however, raise constitutional issues, including how fundamental rights and the Bundestag’s responsibility of control can be secured. The project aims to develop starting points for legal solutions to these questions.
Beyond the analysis of specific forms of deployment, the project seeks to determine the particular features of the structural principles of constitutional law governing foreign affairs as they apply in the field of external security, especially with regard to the application of fundamental rights and the separation of powers. The project proceeds from the observation that a significant transformation is currently taking place, which may be described as a constitutional ‘normalisation’ of foreign affairs. ‘Normalisation’ refers to tendencies moving away from the long-dominant exceptionalism according to which fundamental constitutional principles can only have limited effect in the sphere of foreign affairs. These developments reveal considerable tension between maintaining the state’s capacity to act in foreign affairs and the increasing juridification of external action. Managing these tensions requires carefully calibrating the relevant principles in a way that is sensitive to the differing contexts and requirements governing the exercise of public authority at home and abroad.
The project is funded by the German Research Foundation (DFG) (project number 573012710).
Publications
Marxsen, Christian, ‘Verfassungsrechtliche Regeln für Cyberoperationen der Bundeswehr: Aktuelle Herausforderungen für Einsatzbegriff und Parlamentsvorbehalt’ (2017) 72 Juristenzeitung 543–552.
Marxsen, Christian, ‘Der Binnenmarkt der Rüstungsgüter’ (2021) 56 Europarecht 307–321.
Marxsen, Christian, Verrechtlichte Kontrolle. Überlegungen zur juristischen Aufarbeitung von Auslandseinsätzen, Verfassungsblog, 22 March 2022 https://verfassungsblog.de/verrechtlichte-kontrolle/.
Wentker, Alexander and Marxsen, Christian, ‘Extraterritoriale grundrechtliche Schutzpflichten. Zugleich Besprechung von BVerfG, Urteil v. 15. Juli 2025 – 2 BvR 508/21 (Drohneneinsatz Ramstein)’ (2025) 80 Juristenzeitung 813–823.
Wentker, Alexander, ‘Verwaltungsgerichtlicher Eilrechtsschutz gegen Rüstungsausfuhrgenehmigungen: strategische Prozessführung und Gewaltenteilung’ (2025) 44 NVwZ 547–552.
Wentker, Alexander, ‘Schutzpflichten und Drittschutz bei Rüstungsausfuhrgenehmigungen – Anmerkung zu BVerfG, Beschluss v. 3.2.2026 – 2 BvR 1626/25’ (2026) 81 Juristenzeitung 356–360.
Wentker, Alexander, ‘Art. 87a GG’ in Eisentraut/Botta/Gebhard/Ruschemeier (eds), Grundgesetz-Kommentar (2026, forthcoming).