Most of the intercepts in 2021 occurred in the Baltic region, where NATO operates an air-policing mission for Estonia, Latvia, and Lithuania. NATO has similar missions for Albania, Montenegro, North Macedonia, and Slovenia. Allies also help to police the skies of Romania, Bulgaria, and Iceland. Generally, intercepts occurred without incident as NATO planes take off to identify the approaching aircraft and escort it out of the area. Very few intercepted flights entered Allied airspace.
Across Europe, over 60 NATO jets are on high alert at all times, ready to respond to unannounced military flights, as well as to civilian aircraft losing communication with air-traffic controllers for any reason – which could range from technical problems to hijacking. NATO has two air operations centers – one in Germany, covering northern Europe, and one in Spain covering the south – which monitor all air movements across Europe.