Arms control

This map layer shows where the Treaty on Open Skies has been ratified. The Treaty on Open Skies, or “Open Skies Treaty”, is a cooperative arms control agreement that came into force on 1 January 2002. It enables participants to fly over other member states along previously agreed routes for photographic, radar and infrared surveillance. The participating states undertake to permit mutual aerial inspection flights on agreed terms concerning the number of permissible flights conducted by each party and the methods used. The Open Skies Treaty has been an important instrument for building mutual understanding and trust between NATO and the countries of the former Warsaw Pact, for instance when monitoring compliance with the Treaty on Conventional Armed Forces in Europe (CFE Treaty), but it has also served to defuse conflicts and enable observation flights for crisis management and environmental monitoring. The idea of setting up this agreement dates back to 1955 when US President Dwight D. Eisenhower proposed such an arrangement to the Soviet leadership. However, fears of espionage delayed its realization until 2002. Germany’s Open Skies-capable aircraft, a Tupolev Tu-154M, crashed mid-air in 1997 and the German Government has since conducted inspection flights using rented or borrowed aircraft.