Open Skies Treaty

  • 26 May 2020

  • On 21st May, 2020, the United States announced its intention to withdraw from the Open Skies treaty (OST).

Reasons for Withdrawal

  • United States and Russia have long accused the other of breaching its terms.
  • For ex, in 2014, Moscow imposed an unpermitted 500-kilometer limit on flights over the strategically important enclave of Kaliningrad.
  • Russia also denied a U.S.-Canadian flight over its “Tsentr” military exercise in September 2019.
  • Washington declared Russia in violation of OST in 2017 and restricted Russian access to Hawaii and Alaska in retaliation.
  • Part of the reason is that US is able to obtain equally good or better data from its satellites. No other country can match US’s satellite monitoring capabilities.
  • For the US, the OST is not particularly useful as an intelligence gathering tool, but the reality is that it was always intended as a confidence building and transparency measure.
  • As tensions between US and Russia have grown, US have become more interested in restricting transparency over its territory.

About Open Skies Treaty

  • First proposed in 1955 by former US President Dwight Eisenhower as a means to deescalate tensions during the Cold War, the landmark treaty was eventually signed in 1992 between NATO members and former Warsaw Pact countries following the demise of the Soviet Union.
  • The idea was to promote openness and transparency of military forces and activities by "mutual aerial observation".
  • It is aimed at building confidence and familiarity among the countries
  • The treaty entered into force on January 1st , 2002, and currently 34 states are party to the treaty while a 35th , Kyrgyzstan, has signed but not ratified it.

Key Points

  • Under the treaty, a member state can “spy” on any part of the host nation, with the latter’s consent.
  • A country can undertake aerial imaging over the host state after giving notice 72 hours before, and sharing its exact flight path 24 hours before.
  • The information gathered, such as on troop movements, military exercises and missile deployments, has to be shared with all member states.
  • Only approved imaging equipment is permitted on the surveillance flights, and officials from the host state can also stay on board throughout the planned journey.
  • The Open Skies Consultative Commission (OSCC), comprised of representatives of all states-parties, is responsible for the implementation of the Open Skies Treaty.


  • The OST was signed in 1992, much before the advent of advanced satellite imaging technology which is currently the preferred mode for intelligence gathering.
  • Yet, surveillance aircraft provide key information that still cannot be gathered by satellite sensors, such as thermal imaging data.
  • Also, since only the US has an extensive military satellite infrastructure, other NATO members would have to rely on Washington to obtain classified satellite data, which would be more difficult to obtain compared to OST surveillance records that have to be shared with all members as a treaty obligation.

Impact of US Withdrawal


  • There may be collateral costs of OST withdrawal; the treaty itself may survive without U.S. participation, but Washington’s exit will diminish the agreement’s value to Russia significantly.
  • Moscow’s withdrawal would probably kill OST, ending a key source of intelligence for many NATO allies.
  • This unilateral U.S. move, taken over its allies’ objections, is likely to damage NATO cohesion.
  • S. departure would also further weaken the international arms control architecture and be a further blow to any global sense of stability.

Uncertainty over Nuclear Related Treaties

  • The first is Intermediate-Range Nuclear Forces (INF). In August, 2019, US exited the INF treaty the West had signed with Russia citing distrust of the latter.
  • The US withdrawal from OST shows that the US may not renew the New Start Treaty due to expire in February 2021.
  • The second is the Comprehensive Test Ban Treaty which was concluded in 1996 but has not entered into force.
  • It prohibits countries from carrying out nuclear test explosions but earlier this year US voiced suspicions that both Russia and China were carrying out low yield nuclear tests in violation of the understanding on zero-yield threshold.
  • US has signed but not ratified the CTBT and there are indications that it may be planning to test.

Way Forward

  • The US should reconsider its intention to withdraw from the OST. Washington profits from this “military-to-military engagement tool” as it contributes to greater transparency and stability in the Euro-Atlantic region. While the intelligence and confidence building advantages are limited for the United States itself, they are very real for America’s NATO Allies.
  • State Parties should return to full compliance with the treaty. They should remove all restrictions that they have unilaterally imposed on Open Skies flights.
  • In particular, parties should give consideration to the provisions on the implementation of status neutral confidence- and security-building measures (CSBMs).
  • European State Parties should make every effort to remain in the treaty, even if the United States withdraws.
  • According to Article XV.3 of the treaty, if the United States withdraws, Canada and Hungary must convene a conference of the States Parties no less than 30 days and no more than 60 days after they have received a withdrawal notice. Parties should adopt a position of maximum flexibility.
  • Should the United States withdraw from the Open Skies Treaty, remaining State Parties must make a determined effort to consider its effect on the treaty.