Today the United States, along with Canada and 22 European nations, signed the Treaty on Open Skies in Helsinki, Finland.
In May of 1989, at a time when the immense changes seen in Europe over the past 3 years were just beginning, President Bush proposed that the nations of the North Atlantic Treaty Organization (NATO) and the former Warsaw Pact agree to open their territories to frequent overflights by observation aircraft from the other side. The United States believes that the greater transparency in military activities brought about by such an agreement will help reduce the chances of military confrontation and build confidence in the peaceful intentions of the participating States.
The Open Skies Treaty is the most wide-ranging international confidence-building regime ever developed, covering the entire territory of North America and nearly all of Europe and the former Soviet Union. Its arrangements for observation flights using photographic, radar, and infrared sensors and its provisions for sharing among participants the information gathered are innovative means to help promote openness and stability in Europe in these uncertain times. Open Skies could also serve as a basis for similar arrangements in other regions of the world where there is a need to build confidence.
The treaty establishes an Open Skies Consultative Commission. In early April it will convene in Vienna, Austria, to complete work on outstanding technical and cost issues regarding treaty implementation. The treaty will be submitted to the United States Senate for its advice and consent to ratification once this work is finished to the satisfaction of all participants.
George Bush, Statement by Press Secretary Fitzwater on the Open Skies Treaty Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/267473