By Juliet Michaelsen, Max Kampelman Fellow Recently, a somewhat obscure security and confidence-building measure returned to the headlines. In October 2019, reports surfaced that the Trump Administration was considering withdrawing from the Treaty on Open Skies, an overflight arrangement designed to boost military transparency and stability across 34 signatories in North American and Eurasia. What is the Open Skies Treaty? In 1955, President Eisenhower first proposed that the United States and Soviet Union allow aerial observation flights over each other’s territories to reduce the risk of miscommunication and subsequent war. Although initially rejected by the Soviets, the idea of Open Skies was revived by President George H.W. Bush in 1989. Bush built on Eisenhower’s vision, suggesting the agreement not just be between the United States and the Soviet Union, but also between NATO and the Warsaw Pact. In 1992, the Open Skies Treaty was signed by the United States, Canada, Russia, and 21 European states. Since the treaty entered into force in 2002, membership has increased to 34 states. The treaty requires that all participants allow observation aircraft to fly over their territory to observe and take pictures of military forces and activities. These images are shared with the observing and observed states, and available for purchase by other treaty signatories. The Open Skies Treaty’s fundamental purpose—enhancing military transparency and cooperation—flows from the same set of commitments that underpin both the Helsinki Commission and the Vienna-based Organization for Security and Cooperation in Europe (OSCE). As Alexandra Bell noted during a Helsinki on the Hill podcast on Open Skies, this “increased openness between militaries will reduce tensions between states and limit the probability of conflict [because] if you know what another country has, if it’s clearly observable to you, you don’t have to plan for things that you’re just guessing about.” Assessing the Treaty During the treaty’s almost 18 years of implementation, the parties have conducted over 1,500 observation flights. The cooperation required to solve logistical problems (such as air traffic control) and inspect planes is one important confidence-building measure. Another is the fact that host countries also have personnel on any observation flight, thus ensuring the flight stays within its agreed plan. This collaboration increases mutual trust and encourages cooperation. Additionally, the Open Skies Consultative Commission, the implementing body of the Open Skies Treaty based at the Organization for Security and Cooperation’s (OSCE) headquarters in Vienna, provides one of the few remaining forums where the United States and Russia can discuss problems and collaborate on solutions. The treaty also allows the United States to provide an important benefit to its allies and partners, who typically ride on flights conducted by the United States. Specifically, as Rep. Emmanuel Cleaver II noted during a joint hearing of the Helsinki Commission and the House Foreign Affairs Subcommittee on Europe, Eurasia, Energy and the Environment, the treaty “allows even small countries a way to get information on military activities around them [which] has been even more important given the Kremlin’s propensity to violate established borders.” One notable example came in December 2018 after Russia attached Ukrainian naval vessels near the Kerch Strait. The United States undertook an Open Skies flight, which was “intended to reaffirm U.S. commitment to Ukraine and other partner nations,” according to the Department of Defense, a message underscored by the flight’s inclusion of personnel from Canada, Germany, France, the United Kingdom, Romania, and—crucially—Ukraine. The Open Skies Treaty also has heightened transparency, specifically between the United States and Russia. Both countries have conducted numerous observation flights over the other’s territory. The United States and its allies have flown about 500 flights over Russia since the treaty’s implementation, including 16 in 2019 alone. According to the State Department, the United States participated in nearly three times as many flights over Russia as Russia has over the United States. The images captured by these flights serve as a crucial, credible, unclassified source of information about Russian forces at a time when Europe and the United States are often uneasy about Russia’s intentions. The Open Skies Treaty does face criticism by some politicians and analysts. For example, a Senate resolution introduced by Sens. Ted Cruz and Tom Cotton calls for the United States’ withdrawal from the Open Skies Treaty, citing Russia’s partial non-compliance as a major problem the treaty. Specifically, Russia has restricted Open Skies flights over its military hub in Kaliningrad and restricted the conduct of flights near its border with South Ossetia and Abkhazia. However, the State Department does not consider these problems insurmountable and has taken many steps to address these issues, including bringing the problem to the Open Skies Consultative Committee, restricting Russian flights over Hawaii, and denying access to two United States airbases. The Future of the Open Skies Treaty In the wake of President Trump’s reported plan to withdraw the United States from the Open Skies Treaty, many members of Congress have expressed support for the agreement and warned of the dangers of withdrawal. House Foreign Affairs Committee Chairman Rep. Eliot Engel first sounded the alarm in a publicly released letter to National Security Advisor Robert O’Brien on October 7, 2019. In the letter, Engel expressed concern about such reports and argued that “American withdrawal would only benefit Russia and be harmful for our allies’ and partners’ national security interests.” Soon after, numerous members of Congress came together to urge foreign policy officials to keep the treaty. House Armed Services Committee Chairman Rep. Adam Smith and Sens. Robert Menendez and Jack Reed (the ranking members of the foreign relations and armed services committees, respectively), joined Rep. Engel in writing a letter to Secretary of State Pompeo and Secretary of Defense Esper, highlighting the importance of Open Skies. A similar letter was sent to Secretary Pompeo by 11 Democratic senators two weeks later. In November 2019, Helsinki Commission Chairman Rep. Alcee L. Hastings co-sponsored the bipartisan “Open Skies Treaty Stability Act,” which would prevent the president from unilaterally withdrawing the United States from the treaty by setting conditions on any potential steps towards withdrawal. The bill specifically notes that “due to the significant benefits that observation missions under the Open Skies Treaty provide to the United States and United States allies, the United States should commit to continued participation in the Treaty; and the President should not withdraw the United States from the Open Skies Treaty.” Support for the Open Skies Treaty extends beyond Capitol Hill. For example, in an October 20, 2019, Wall Street Journal contribution, former-national security officials George Shultz, William J. Perry and Sam Nunn suggested that “Open Skies has become what Eisenhower envisioned—a critical confidence-building treaty that improves Euro-Atlantic security with every flight. The U.S. should preserve this agreement, particularly in a time of renewed tensions with Russia.”  Similar calls have come from abroad. The Political and Security Affairs Committee Chair of the OSCE Parliamentary Assembly (OSCE PA) strongly urged the United States to stay in the treaty, citing the increased transparency and cooperation fostered by the agreement. Meanwhile, Ukraine’s Foreign Ministry expressed their interest in “maintaining and implementing this treaty” in a statement to the Wall Street Journal. The vocal advocacy both within and outside of the United States for the continuation of the Open Skies Treaty sheds light on its important role in Euro-Atlantic security and cooperation.