U.S. military officials recently appeared to question American participation in the Treaty on Open Skies. At a House Armed Services subcommittee hearing on February 24, Admiral Cecil D. Haney, commander of Strategic Command, testified that he was “concerned in terms of overflights of any ability of another nation to learn more about our overall critical infrastructure.”

This followed on the heels of the Russian submission of a request to equip its Tu-154 Open Skies surveillance aircraft with digital electro-optical sensors. At a House Armed Services committee hearing on March 2, Lieutenant General Vincent Stewart, director of the Defense Intelligence Agency, testified that the “digital techniques allow Russia, in my opinion, to get incredible foundational intelligence on critical infrastructure, bases, ports, all of our facilities, so from my perspective, it gives them a significant advantage.”

This apprehension about new Russian sensors comes as something of a surprise. The Open Skies transition to digital sensors has been discussed in the context of the treaty for a decade, and U.S. officials play a significant role in the lengthy certification process for new sensors. The United States, moreover, is currently developing digital sensors for its Open Skies surveillance aircraft. 

Blue skies

The Open Skies Treaty, negotiated at U.S. initiative, entered into force in 2002 and has 34 States Parties. The treaty is designed to enhance openness and transparency by allowing States Parties to fly unarmed aerial observation flights over the entire territory of participating states. It makes a major contribution to confidence-building, particularly in Europe. More than 1,100 observation flights have been carried out since the treaty came into force. 

The United States and its allies have benefited immensely from the treaty and the transparency it provides. For example, according to Principal Deputy Assistant Secretary of State for Nuclear and Strategic Policy Anita E. Friedt, almost a dozen U.S. and NATO member flights over Ukraine and Western Russia in 2014 during the Ukraine crisis “resulted in valuable data and insights.”

The United States and its allies have benefited immensely from the treaty and the transparency it provides.


Unfortunately, Russia has failed to meet some treaty obligations. As stated in the State Department’s “2015 Report on Adherence to and Compliance With Arms Control, Nonproliferation, and Disarmament Agreements and Commitments,” Moscow is not “allow[ing] effective observation of its entire territory by refusing access in three areas,” including restrictions over/near Chechnya, along the Russia-Georgia border, and over Kaliningrad. While selective implementation impacts the strength of the treaty, it continues to benefit the United States and play a vital role in Euro-Atlantic security along with the Vienna Document on confidence- and security-building measures. 

Digital sensors: Not exactly news

The first time digital sensors were discussed in Open Skies Consultative Commission (OSCC) documents was in 2007, when the Informal Working Group on Sensors was working on a decision regarding new digital image processing. 

During the 2010 Second Review Conference on the Implementation of the Treaty On Open Skies, participants acknowledged that technological advancements “in the world of sensors require[d] States to transition from film-based cameras to digital cameras in the near future,” and agreed to examine sensor replacement options. According to the U.S. Air Force, wet film cameras are becoming “nearly obsolete, frequently unreliable, hard and increasingly expensive to maintain,” making the transition to digital sensors necessary.

Last June during the Third Review Conference, Under Secretary of State for Arms Control and International Security Rose Gottemoeller said “States Parties have made a good start in the transition to digital sensors which was initiated by the Russian Federation.” She added: “I want to thank everyone who has worked so hard this past year to reach agreement on improved technical decisions for future certification events that will involve digital sensors.”

Upgrades underway

A Department of State spokesperson told the TASS Russian news agency on February 24 that the United States “has initiated a process to procure a digital electro-optical sensor for its Open Skies aircraft.” This process was begun in compliance with the requirements in Presidential Policy Directive-15 (PPD-15), which called for the United States to begin procuring digital-optical sensors. 

In the Air Force budget from February 2015, the budget item justification for project “OC-135 Open Skies Sensors” detailed that digital sensors are “more reliable, maintainable and cost effective,” and will result in products that the “customer will be able to more readily use.” The project timeline listed that final operational capability will be completed in late 2019. This means the United States will have similar sensors to Russia in three years. 

A thorough process

To have its digital sensors approved, a State Party needs to submit a data package of technical information pertaining to its aircraft and sensors to all State Parties. The State Party then needs to show the procedures, processes, and technical capabilities of the new sensors in a pre-certification event. It needs to demonstrate procedures such as how the digital images are processed and duplicated (the Open Skies Treaty requires that the State Party conducting the surveillance flight provide a copy of the images it takes to the state that has been overflown). The State Party also must allow other state representatives to examine the aircraft, sensors, and processing systems. If any State Party requests, the Informal Working Group on Certification will convene a meeting where the State Party will address and clarify any questions others may have. U.S. officials thus have several opportunities to raise potential concerns about Russian digital sensors. 

Because the certification process has started, U.S. officials already have information about the capability of Russia’s new sensors. According to both State Department and Joint Chiefs of Staff officials, the Russian digital sensors were within the scope of the treaty, and the only changes were the transition from wet film to digital, without introducing additional capabilities. 

So, what’s the debate really about?

The Russians are not seeking to change the rules of the game. Russia is doing the same thing the United States is doing; the Russians just happen to have operationalized the capability first. One thus has to wonder whether this debate is about the new Russian sensors, or whether it is about the value of the treaty itself.

Critics of the treaty argue that, since the United States has sophisticated satellite systems, Russia benefits more from the treaty’s transparency than does the United States. This is not necessarily true, for two reasons: First, the United States as a country and society is much more open and transparent than Russia. The treaty offers valuable opportunities to gain information about Russian military forces and activities of concern to the United States, its allies, and other European states.

Russia is doing the same thing the United States is doing; the Russians just happen to have operationalized the capability first.

Second, as former Secretary of State George Shultz and others wrote in 2012, “for countries without sophisticated satellite systems, Open Skies is their only means of alleviating security concerns through timely overhead imagery.” A number of our allies rely on Open Skies for imagery collection. It remains in the U.S. interest to continue observing the treaty, which contributes to confidence-building, stability, and predictability in Europe, which has become more troubled and tense in the last few years. 

The U.S. government has known this turning point in the Open Skies Treaty was coming for several years, so questions about Russia trying to switch to digital sensors miss the mark. The United States should consider the overall value to the treaty and should not reduce its compliance. Others could well follow. Losing this important treaty and its contribution to confidence-building in Europe would weaken U.S. security and of that of its allies.