The Treaty on Open Skies was signed on 24 March 1992 by 27 states in NATO and the former Warsaw Pact; it entered into force as a legally binding document on 1 January 2002.
The Treaty gives each State Party the right to conduct a certain number of agreed observation flights a year over the territory of other States Parties. Sensors for photo and video images are used during these flights, along with more and more digital sensors.
Because representatives of both the observing and the observed states participate in all observation flights, the Treaty plays an important role in creating transparency and building confidence. Observation flights can also be used to obtain a picture of the situation in international crises as well as for monitoring the environment.
More than 1,500 observation flights have been conducted under the Open Skies regime to date. Germany has been involved in more than 12% of these flights. In 2015, Germany took the decision to acquire and operate a new, national observation aircraft. Now that Germany has taken delivery of this plane, it will be available for observation flights as of 2021.
The Open Skies Consultative Commission (OSCC), which is based in Vienna and maintains several informal working groups, is the primary consulting and decision-making body for issues related to implementing and further developing the Treaty on Open Skies. At the national level, the Bundeswehr Verification Centre (ZVBw) is responsible for coordinating, processing and assessing the images that are collected during all Open Skies missions that involve Germany.
After additional countries signed the Treaty on Open Skies in 2002 and 2003, the United States became the first State Party to declare its withdrawal from the Treaty in May 2020. This move took effect on 22 November 2020. Foreign Minister Maas issued the following statement on the withdrawal:
I very much regret the announcement by the US Administration. This pact is an important element of Europe’s arms control architecture. We understand that there have indeed been difficulties with respect to implementation on Russia’s part. However, from our point of view that does not justify withdrawing from the Treaty. I and my counterparts in France, Poland and the UK have repeatedly informed US Secretary of State Pompeo that this is our position. (...) Our course of action is clear. We will continue to adhere to the Treaty and will do everything we can to preserve it.