Open Skies Over Benelux And Germany
Cold War kids like me still remember the Open Skies treaty, the 1992 agreement by members of NATO and the then Warsaw Pact to allow observation flights over their territory as a confidence-building measure.

Belgian Defense photo by Patrick Brion
Last week, a Russian Antonov An-30B conducted flights over Belgium, the Netherlands and Germany. On March 16, the Russian aircraft arrived in Melsbroek, Brussels' military airport, the only Belgian military base designated for observation flights to be conducted from.
The next day, after members of the Benelux Arms Control Agency (BACA) checked the Russian flight plan and coordinated it with Belgian, Dutch and German air traffic control, the Antonov flew over the Netherlands on the way to Ingolstad air base in Germany. Over the next few days, the Russian observation aircraft flew from Ingolstadt to Cologne-Bonn and from there back to Melsbroek, which it left March 21.
The Russian crew was guided by members of BACA and their German equivalent. The BACA members practiced for their task three weeks before the Russian Open Skies mission during a training flight with U.S. and British personnel.