The Treaty on Open Skies has been an important legal instrument contributing to global arms control in recent years. Signed in 1992, the Treaty on Open Skies allows the monitoring and collection of data on military potential through observation flights over one another’s territories, thus becoming a confidencebuilding and transparency measure among its signatories. The recent decisions by the US and Russia to withdraw from this agreement impact the security situation globally and regionally. They reflect a gradual erosion of the architecture of arms control that has been introduced since the end of the Cold War. Georgia remains the only state in the South Caucasus to be a signatory to this Treaty. It is also the only state in the region to remain (since 2008) in a conflict with Russia. While striving to join the EU and NATO, it lies on the land of strategic importance to Russia and other regional and global players. The main objective of this publication is to discuss the importance of the Treaty on Open Skies, considering its specificity from a regional perspective, and to assess the implications of the withdrawals of the US and Russia from the Treaty on security in Georgia and in the South Caucasus. Using a descriptive approach and legal-political analysis, the author discusses the creation, functioning, and causes of the breakdown of this legal-institutional system, while looking at its importance for global arms control and security related consequences it may trigger for the region. A closer look at the South Caucasus highlights the author’s belief in the Treaty’s critical role in the region and the importance of preserving its existence.