The AWACS involvement in exercise "Aviation Detachment Rotation 20-4" is a long planned activity, involving flights over Allied territory. It is part of and mandated under NATO's Assurance Measures, implemented in 2014 after Russia's illegal and illegitimate annexation of Crimea. These measures are in place to assure the Alliance's eastern members of NATO's commitment and solidarity, as well as to deter any possible aggression against NATO members.
Based at Geilenkirchen Air Base in Germany, NATO's fleet of 14 AWACS aircraft conducts a wide range of operations – including flights in support of the Global Coalition to Defeat ISIS, as well as Operation Sea Guardian. They regularly conduct flights under NATO's Assurance Measures across the implementation area, including air surveillance flights, exercise support, or "show of presence" such as fly-overs.
A NATO AWACS being prepared for take-off - Photo by Cynthia Vernat.