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FACTBOX: Treaty on Open Skies

Until now, 33 out of 57 OSCE member states were parties to the Treaty

MOSCOW, June 7. /TASS/. On June 7, 2021, Russian President Vladimir Putin signed a decree on denouncing the Treaty on Open Skies.

Treaty’s history

The Treaty on Open Skies grants its participants the right to fly over each other’s territory to observe military activity.

The proposal to exchange military information and check it by mutual aerial photographic surveying was first put forward by US President Dwight Eisenhower at a conference of the heads of four powers (the Soviet Union, the United States, Great Britain and France) in Geneva on July 21, 1955. As Eisenhower put it, this idea could open a small gate in the wall of disarmament. The negotiations began in the late 1950s but were terminated after an incident with a US U-2 spy plane in May 1960 (it was shot down in the Soviet airspace). In the spring of 1989, US President George H. W. Bush proposed that the leadership of the member states of NATO and the Warsaw Pact return to discussing this issue. The first two rounds of negotiations were held in 1990 in Ottawa (Canada) and Budapest (Hungary). After that, the negotiating process continued in Vienna in 1991 and 1992.

The document was initialed in Vienna on March 21, 1992. On March 24, 1992, it was signed in Helsinki by representatives of 27 member states of the Conference on Cooperation and Security in Europe (the European states and also the United States and Canada; the Organization for Security and Cooperation in Europe (OSCE) since 1995). The Treaty went into force on January 1, 2002 after 20 countries ratified it (Russia ratified the Treaty on May 26, 2001).


Until now, 33 out of 57 OSCE member states were parties to the Treaty: Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Russia, Slovakia, Slovenia, Spain, Sweden, Turkey, Ukraine and the United Kingdom. Kyrgyzstan signed the Treaty but has not ratified it.

The United States withdrew from the Open Skies Treaty on November 22, 2020.

Basic provisions

The document regulates the conduct of flights, stipulates requirements for observation aircraft and equipment and establishes the rules of processing the data collected. The information that is gathered is entered into the database accessible to all the participating states. The Open Skies Treaty may be extended into additional fields, such as environmental protection, emergencies, monitoring of the territory and the conflicting parties’ actions within the framework of the OSCE peacekeeping operations.

The flight path of an observation aircraft must not be closer than 10 kilometers from the border of an adjacent state that is not a member state. The Treaty permits setting up groups. Thus, Russia and Belarus comprise one group of member states while Belgium, the Netherlands and Luxembourg make up another group.


The Treaty assigns a certain amount of quotas to each member state (including active quotas when a country conducts inspection flights over the territory of another state and passive quotas when it accepts other states’ inspections). The United States (before its pullout from the Open Skies Treaty) and the group of Russia and Belarus had 42 flights a year each. Germany, Canada, France, the United Kingdom, Italy, Turkey and Ukraine had 12 flights each. Portugal has the smallest quota of 2 flights. The quota may not be wholly used for flights over only one state.

Aircraft and airfields

An observation aircraft is not outfitted with any armaments. The equipment installed on the aircraft (aerial photography sensors) pass certification by representatives of the Treaty’s member states, which excludes the possibility of using technical means that are not stipulated in the Treaty. Representatives of the observed party are always present aboard an aircraft. The Treaty stipulates the option of using the aircraft of an observed party. An observation flight is conducted from a specific airfield. In Russia, such airfields are located in Kubinka (the Moscow Region), Ulan-Ude, Magadan and Vorkuta. A maximum flight distance is stipulated for observation flights from each of the airfields.

Russia used specially equipped Tu-214ON, An-30 and Tu-154M-Lk-1 planes for observation flights. The United States operated Boeing OC-135B Open Skies aircraft for inspections.

Ban on flights

The Treaty does not stipulate any restrictions on observation flights for considerations of secrecy, national security and so on. However, pursuant to Article VIII, the observed party has the right to prohibit an observation flight, if it violates the procedures stipulated in the document, the requirements for the aircraft’s equipment or the route. The Treaty does not envisage any sanctions against the observed party for the prohibition of flights.

Consultative Commission and Review Conferences

The Open Skies Consultative Commission comprising representatives of the member states was set up with its headquarters in Vienna (at the OSCE Secretariat) for practically implementing the Treaty’s provisions. The Consultative Commission meets for no fewer than four regular sessions a year while extraordinary sessions are convened at the request of one or more member states. The Commission’s decisions are passed by consensus and have a binding force. Under the Open Skies Treaty, a conference of the participating states is convened every five years to review the document’s implementation. The first review conference took place in February 2005, the second in June 2010, the third in June 2015 and the fourth in October 2020.

Treaty’s implementation in 1990-2020

The provisions of the Treaty began to be practically checked even before the document went into force. The first Open Skies trial flights were conducted by Canada and Hungary in 1990. The first trial flight over Russian territory was conducted jointly by Russia and the United Kingdom in 1992. From March 24, 1992 to December 31, 2001, the regime of the Treaty’s provisional application was in effect. In 2011, Georgia unilaterally announced it was ceasing cooperation with Russia under the Treaty over the conflict around the political status of Abkhazia and South Ossetia. About a hundred observation flights were conducted annually over the territory of the Treaty’s participating states.

Mutual claims by US and Russia, Washington’s withdrawal from the Treaty

For several years, the United States had been accusing Russia of violating some provisions of the Treaty, in particular, of restricting observation flights by the 500 km range over the Kaliningrad Region and in the 10 km zone along the borders with Abkhazia and South Ossetia. Russia explains the restriction over the Kaliningrad Region by the fact that Open Skies long observation flights close the region’s entire airspace for civil aviation. As for Abkhazia and South Ossetia, Russia recognizes them as independent states and, consequently, flights closer than 10 km from the border with them are prohibited under the Treaty. Other countries consider them as the territory of Georgia and, therefore, this is an issue of international relations and may not be viewed as a breach of the Open Skies Treaty. For its part, Moscow laid claims to Washington for complicating the procedure of agreeing upon and restricting observation flights, in particular, over the Aleutian and Hawaiian Islands.

Open Skies Treaty after US pullout

The European member states of the Open Skies Treaty expressed their regret over Washington’s decision to pull out from the document (the United States announced its move on May 21, 2020). In their joint statement of May 22, 2020, 11 Western European countries stressed that the Treaty was a major element of the system of confidence-building measures that had been set up in the past few decades to raise transparency and security in the Euro-Atlantic region. Germany, France and Great Britain stated their commitment to the document.

Russia pointed out after the US exit from the document that NATO member states were still parties to the Open Skies Treaty, which allowed Washington to get information from these countries while Russia would be banned from conducting observation flights over US territory. Russia’s Foreign Ministry stated that Moscow put forward "specific proposals compliant with the fundamental provisions" of the Open Skies Treaty for keeping it viable but received no support from US allies.

On January 15, 2021, Russia’s Foreign Ministry said in a statement that Moscow was launching internal procedures for exiting the document and this decision was made due to the disruption of "a balance of interests of its member states achieved upon the Treaty’s conclusion" and the absence of progress in removing obstacles for continuing its fulfillment.

On April 6, 2021, the US military made a decision to dismantle the aircraft that Washington had used under the Open Skies Treaty to conduct observation flights over Russia.

On May 27, 2021, the United States notified Russia of its decision against rejoining the Treaty on Open Skies.

Procedure for Russia’s withdrawal from the Treaty

Russia’s Foreign Ministry announced on January 15, 2021 that Moscow had launched internal state procedures for exiting the Treaty on Open Skies. The Russian diplomatic agency explained that Moscow had taken this step due to Washington’s denunciation of the Treaty and "the absence of progress in stabilizing the document’s effect."

On May 11, 2021, Russian President Vladimir Putin submitted a bill to the State Duma (the lower house of Russia’s parliament) on denouncing the Open Skies Treaty. The text of the bill said that this decision had been made in the wake of the US pullout from the document on November 22, 2020, "which substantially disrupted the balance of interests of the Treaty’s member states" and "caused serious damage to the Treaty’s observance and its significance in strengthening trust and transparency," following which "a threat emerged to the national security of the Russian Federation."

On May 19, 2021, the State Duma unanimously adopted the bill submitted by the Russian president. On June 2, the bill on denouncing the Open Skies Treaty was unanimously approved by the Federation Council (the upper house of Russia’s parliament).