The 34 States Parties to the Open Skies Treaty are: Belarus, Belgium, Bosnia-Herzegovina, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Russian Federation, Slovak Republic, Slovenia, Spain, Sweden, Turkey, United Kingdom, Ukraine, and United States. Kyrgyzstan has signed but not yet ratified. The Treaty depositaries are Canada and Hungary.
The Treaty is of unlimited duration and is open to accession by other States. States of the former Soviet Union which have not already become States Parties to the Treaty may accede to it at any time. Applications from other interested States are subject to a consensus decision by the Open Skies Consultative Commission (OSCC), the Vienna-based organization charged with facilitating implementation of the Treaty, to which all States Parties belong. Eight states have acceded to the Treaty since entry into force: Finland, Sweden, Latvia, Bosnia-Herzegovina, Croatia, Slovenia, Estonia, and Lithuania. One application for accession is pending before the OSCC.
Basic Elements of the Treaty
The Open Skies regime covers the territory over which the State Party exercises sovereignty, including - land, islands, and internal and territorial waters. The Treaty specifies that the entire territory of a State Party is open to observation. Observation flights may only be restricted for reasons of flight safety, not for reasons of national security.
Observation aircraft may be provided by either the observing Party or by the observed Party (the "taxi option"), at the latter's choice. All Open Skies aircraft and sensors must pass specific certification and preflight inspection procedures to ensure that they are compliant with Treaty standards. Certified Open Skies aircraft include: