“Open Skies will strengthen international stability… and provide an important means of increasing mutual understanding.”
President George H. W. Bush
How an extraordinary post-Cold War treaty turned military surveillance into an instrument of trust — and what its decline tells us about great-power rivalry today
Imagine Russian military aircraft being permitted to fly across the United States photographing military installations, and American reconnaissance aircraft doing the same over Russia. It sounds like espionage, yet for nearly two decades, it was international law.
The Treaty on Open Skies was one of the boldest experiments in military transparency ever attempted. Born from the end of the Cold War, it rested on a radical proposition: “sometimes the best defence against conflict is not greater secrecy, but greater visibility”.
The Geopolitical Scene: A World in Transition
The early 1990s were one of those rare moments when the international system appeared capable of escaping its own history. The Cold War had ended. The Iron Curtain had lifted. The Soviet Union had collapsed.
Yet the disappearance of the Cold War did not mean the disappearance of distrust.
NATO and the former Warsaw Pact still possessed enormous military establishments. Nuclear arsenals remained. States that only recently regarded one another as existential enemies were suddenly expected to coexist. Peace had arrived. Trust had not.
Into this fragile landscape came the Treaty on Open Skies.
The idea dated back to 1955, when President Dwight D. Eisenhower proposed that the United States and Soviet Union permit reciprocal aerial observation of their territories, Moscow rejected it. More than three decades later, President George H. W. Bush revived the proposal as Soviet reforms transformed East-West relations.
Negotiations followed, and on 24 March 1992, 27 countries signed the Treaty on Open Skies in Helsinki. An idea rejected at the height of the Cold War had finally taken flight. Its proposition was extraordinary: “perhaps security could sometimes be strengthened not by hiding military capabilities, but by revealing them”.
What Was the Purpose of the Treaty on Open Skies?
The treaty’s objective was simple: to build trust through transparency.
Participating countries permitted unarmed observation aircraft from other treaty members to fly across their territories and photograph military forces, installations and activities. Its reach stretched from Vancouver to Vladivostok. Membership eventually expanded to 34 countries, bringing together NATO members and former Warsaw Pact states.
Think about what that meant, an American military reconnaissance aircraft could legally fly over Russia. A Russian aircraft could legally fly over the United States.
This was not conventional espionage, while espionage depends upon secrecy, Open Skies attempted something almost opposite: “observation by consent”.
The objective was not merely to gather intelligence. It was to reduce uncertainty, one of the most dangerous variables in international politics.
A military exercise can resemble preparation for invasion. Troop movements can be misinterpreted. New installations can generate rumours about capabilities and intentions.
Open Skies attempted to insert evidence into that dangerous space between perception and reality.
How Open Skies Worked: Engineering Trust
The philosophical ambition of Open Skies depended upon an extraordinarily detailed technical framework. Trust alone was insufficient, Trust had to be engineered.
Observation flights could operate across the territory of participating states, with restrictions principally connected to flight safety rather than a government’s desire to conceal sensitive military areas.
Aircraft had to be unarmed and fixed-wing, while permitted cameras, infrared equipment and radar were subject to strict technical limitations and certification.
Observation rights were also reciprocal, each country had quotas governing how many flights it could conduct and how many it had to accept. The United States and Russia/Belarus, for example, were each allocated 42 annual flights. The principle was clear: if you could look at me, I could look at you.
Mission procedures were equally controlled. Advance notification was required, routes were agreed, equipment was inspected, and representatives of the observed country could accompany flights.
Data gathered during missions could also be made available to other treaty members — particularly valuable for smaller states without sophisticated reconnaissance satellites of their own. In that sense, Open Skies did something unusual. It partially democratised strategic intelligence. The treaty was therefore not simply about allowing countries to observe one another. It created a community of verification.
Did the Treaty on Open Skies Work?
For many years, broadly, yes. From its entry into force in 2002 until October 2019, more than 1,500 observation flights were conducted. These missions provided information about military exercises, troop concentrations, equipment and infrastructure. But the deeper accomplishment was psychological. Every successful flight demonstrated that former adversaries could expose parts of their military establishments to one another without surrendering sovereignty. Flight by flight, mission by mission, image by image. A rhythm of cooperation emerged, but treaties do not exist outside geopolitics, and geopolitics was changing.
Why Did America and Russia Leave Open Skies?
As relations between Russia and the West deteriorated, disputes increasingly affected the treaty. Washington accused Moscow of restricting observation flights over strategically important areas, particularly Kaliningrad, and of limiting flights near portions of the Georgian-Russian border. The United States argued that such restrictions undermined the principle of territorial transparency on which Open Skies depended.
In 2020, Washington announced its withdrawal. The American departure became effective on 22 November 2020.
Russia argued that the US withdrawal fundamentally altered the treaty’s strategic balance. Moscow was particularly concerned that European members could continue observing Russian territory while information might ultimately reach a United States no longer bound by reciprocal obligations. Russia subsequently withdrew in 2021. The two principal military powers around which much of the treaty’s strategic value revolved were gone, and therein lies one of the central lessons of Open Skies. The remaining 32 countries remained, the cameras still worked, the aircraft could still fly, the inspection procedures remained possible.
The Legacy of Open Skies: When Surveillance Became Trust
The Treaty on Open Skies deserves to be remembered as more than another arms-control agreement. It was a philosophical experiment in international security.
Its premise was that visibility could sometimes provide greater security than secrecy.
That challenged one of the oldest instincts of military power. States traditionally protect themselves by concealing capabilities, intentions and vulnerabilities. Open Skies reversed that logic. A Russian aircraft flying across the United States or an American OC-135B crossing Russian territory carried extraordinary symbolism. Neither was invading.
Neither was secretly penetrating enemy airspace, each had been invited, the aircraft themselves became demonstrations of reciprocal restraint.
Through the Clouds, Toward Clarity
There is something almost poetic about the Treaty on Open Skies, Aircraft – among the defining instruments of twentieth-century warfare – became vehicles of reassurance.
Military cameras became instruments of cooperation, foreign reconnaissance aircraft, normally symbols of violated sovereignty, entered national airspace legally and openly.
For a period, adversaries quite literally watched one another watching, more than 1,500 missions demonstrated that the idea could work. Open Skies also demonstrated the limits of arms-control architecture.
No verification system can indefinitely compensate for collapsing political trust, and here lies a wider lesson about global hegemony and the strategic illusion that security can be achieved through dominance alone.
Open Skies asked a different question: could both sides become safer by agreeing to be seen?
The treaty never abolished rivalry. It never eliminated military secrecy. It never transformed adversaries into permanent partners. For a remarkable period, it demonstrated that transparency itself could become a strategic instrument.
The enduring lesson of Open Skies is therefore not that transparency defeated geopolitical rivalry. It is that, for a time, transparency helped make rivalry manageable. The skies may no longer be as open as they once were, but the idea remains.
Perhaps security does not always begin with another weapon, another wall or another layer of secrecy. Sometimes it begins with the courage to be visible – and the willingness to allow an adversary to look back.
Why This Book Matters Now?
With the world once again teetering on the edge of geopolitical rupture, this book is a must-read for scholars, diplomats, strategists—and every citizen who dares to ask, “How did we get here?”
This is your invitation to step behind the veil of power and witness how the illusion was built.
Copyright © 2026 by Bahaa Arnouk. All rights reserved. This article or any portion thereof may not be reproduced or used in any manner whatsoever without the express written permission of the author.
This blog should NOT be read as either an investment, political, legal or a business advice, and it only represents the author’s views (Bahaa Arnouk) and does not represent any other body or organization perspectives, and the author has no liability for any reliance or reference made to it by any third party.