Proceedings of the International scientific and practical conference ―Cambridge Congress of Advanced Studies‖ (April 3-5, 2026) / Publisher website: www.naukainfo.com. - Cambridge, United Kingdom, 2026. - 350 p.

47 investments exceeding €500 billion to support energy and climate transformation. These initiatives demonstrate how global environmental challenges stimulate new forms of regional integration and policy coordination. Regarding security, the EU faces complex geopolitical threats, including growing tensions along its eastern borders, conflicts in neighboring regions, and new forms of hybrid threats, such as cyberattacks and disinformation campaigns. Russia‘s aggression against Ukraine in 2022 highlighted the necessity of strengthening defense mechanisms and deepening cooperation through instruments such as the European Defence Fund and joint military exercises. In addition, the EU actively cooperates with NATO, which enables the coordination of regional security efforts and collective responses to emerging threats. The transformation of the EU‘s regional system occurs under the influence of global economic, environmental, and security challenges, stimulating the development of new integration strategies, strengthening regional cooperation, and encouraging the search for effective solutions to ensure sustainable development and stability within the Union. The EU demonstrates how regional systems can adapt to globalization processes and effectively respond to complex contemporary challenges. Eastern Europe represents a region characterized by complex historical, political, and economic dynamics that determine the specific features of the transformation of its regional system of international relations. Geopolitical instability in the region is driven by a combination of historical disputes, contemporary conflicts, and the active influence of global actors. The primary challenges facing the region include economic dependence on energy resources, military and political tensions, and issues related to sustainable development. The economic landscape of Eastern Europe is highly heterogeneous. Some countries, such as Poland and the Czech Republic, demonstrate stable economic growth; for instance, Poland‘s GDP increased by 5.1% in 2023. Meanwhile, other states in the region face delays in structural modernization and maintain a high level of dependence on energy imports. Energy security remains a critical concern. The war in Ukraine and restrictions on gas supplies from Russia during 2022–2023