The United States has long deployed nuclear weapons in Germany under “programs of cooperation” in which the weapons are maintained under U.S. custody but, in a conflict, and with proper authorization, could be turned over to the German military for use. The current delivery system is the German Air Force’s Tornado aircraft, which is dual-capable — it can deliver both conventional and nuclear weapons — but nearing the end of its service life.
Germany’s upcoming election and the future of nuclear sharing (brookings.edu)