Bulgarian Defense Minister Nenchev witnessed first-hand today a demonstration of joint air policing operations during the media day at Graf Ignatievo Air Base, near Plovdiv. Four U.S. F-15 fighter aircraft arrived in Bulgaria to conduct NATO Air Policing missions jointly with Bulgaria’s MIG-29s September 9-16. NATO air policing is a standing peacetime mission to preserve the integrity of Allied airspace. The enhanced Air Policing is part of the Alliance’s Assurance Measures for eastern Allies. As part of this mission, NATO assets respond to civilian aircraft in distress and non-NATO military aircraft that do not follow international flight regulations in their approach to NATO airspace.