The Open Skies Treaty

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 members to conduct, at short notice, unarmed observation flights over the entire territory of other state parties above all to monitor military facilities, systems and movements. This made the Open Skies Treaty an important instrument for checking on compliance with the Treaty on Conventional Armed Forces in Europe (CFE Treaty). In principle it also enables observation flights to be carried out for wider reasons: crisis management, conflict prevention and environmental monitoring. The aircraft deployed have to be certified by treaty partners and are equipped with sensors to record photographic, radar and infrared images. The Open Skies Treaty is intended to create greater transparency between the participating states and thus help to build mutual confidence. Its implementation is overseen by the Open Skies Consultative Commission (OSCC), which comes under the umbrella of the Organization for Security and Co-operation in Europe (OSCE) in Vienna.

The idea of creating an agreement to enable reciprocal observation from the air was first mooted in July 1955 by US President Dwight D. Eisenhower in a proposal to the Soviet Union. At that time, however, Moscow rejected the proposal, fearing such a treaty would be used as a cover for espionage. As the Cold War began to wane, US President George H.W. Bush revived the idea. Talks between NATO members and the Warsaw Pact states began in February 1990 and ended in the signing of the Open Skies Treaty on 24 March 1992 in Helsinki, Finland.

The first signatories included the following 27 countries: Belgium, Belarus, Bulgaria, Canada, Denmark, Germany, Finland, France, Georgia, Greece, Hungary, Iceland, Italy, Kyrgyzstan, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Russia, Slovakia, Spain, Turkey, Ukraine, the United Kingdom, and the United States. Apart from Kyrgyzstan, they have all since ratified the treaty. Various countries later joined the treaty, including Bosnia-Herzegovina, Croatia, Estonia, Latvia, Lithuania, Slovenia and Sweden. The Open Skies Treaty is expressly open to new members. States that were once part of the Soviet Union can currently join, while applications from other countries require approval by consensus from the OSCC.

There is a quota system to determine the permissible number of observation flights per year. Each state party is accorded its own “passive quota”, which is related to the size of its territory. For Russia and the United States, this quota is 42, for Germany just twelve flights. The passive quota designates the total number of observation flights that a state must approve over its own territory in one year. The Treaty also sets an “active quota” for the maximum number of flights each member country has the right itself to conduct over other territories A member’s active quota may never exceed its passive quota. Since the Treaty came into force, almost 1,000 observation flights have been flown, with the United States and Russia, in particular, making use of the Open Skies arrangement to repeatedly monitor the other side.

The procedures for an observation mission are defined very precisely in the Treaty The “observing” state must provide the “observed” state with a least 72 hours’ notice of an impending mission. Receipt of notification must be acknowledged within 24 hours, with the observed state telling the observing state whether it may use its own aircraft or use one that has been provided. In any event, the observation mission is conducted jointly. In particular, the two sides have to agree on a flight path and specify in advance the starting, refuelling and finishing points. Moreover, the observed country should always comply with the flyover wishes of the observing country unless there are logistical or safety reasons for rejecting a certain route.

If the observing state uses its own aircraft, the observed party has the option of inspecting it in advance to check whether it is in line with treaty rules. Certified observation aircraft must be fitted only with specified sensors, to which every treaty state must generally have access. While these sensors can spot large items of military equipment, they do not have a particularly high resolution. Each mission should be completed within 96 hours of the observation team’s arrival. A copy of all data collected during an observation flight is also supplied to the host country and can be acquired by any other state party.

The first review conference on implementation of the Open Skies Treaty took place from 14 to 16 February 2005, the second on 7 to 9 June 2010. These meetings, held in Vienna under the chair of the United States, reaffirmed the treaty’s key role as an instrument for strategic confidence building. The review process led to a technical update, providing for digital cameras and other digital equipment for the observations. In the medium-term, Open Skies membership is to be expanded to include all OSCE member states.

In Germany, the Bundeswehr Verification Center is entrusted with the planning, execution and evaluation of Open Skies observation missions in which Germany participates. At present, however, Germany does not have a certified aircraft of its own that would be able to conduct such missions. A Tupolev TU154M, operated by the German Air Force, had been fitted with the required sensors and made mission-ready but, on 13 September 1997, it collided with a US-American military aircraft over the South Atlantic and crashed. All 24 persons on board died in the incident. So the federal government has since been conducting control flights with rented or borrowed aircraft.

Sources and further information

• The treaty in full (OSCE)
• The Open Skies Treaty explained on the website of the German Foreign Office (AA)
• Information on the Open Skies Treaty

BICC 11/2013