Cooperation mechanisms in the Danube region are imposed by regional policies but also by competitiveness against the backdrop of synergistic approaches and interconnections between the Danube, the Black Sea, and the European Union for the achievement and consolidation of a sustainable economic ecosystem. The institutional capacity of the Danube riparian states emphasizes the continental interdependence, the states' co-interest in having an integrative role in the geo-economic and geopolitical algorithm of the Danube, but also the chance for the "Romanian Danube" to be identified as an EU-NATO security and security instrument. Combining the military and economic-social role of the Danube, evolves towards a strategy implemented coherently which leads to the reduction of the inevitable economic and security gaps on the entire European continent, but also in terms of infrastructure, ecology, and environment, good governance, and ensuring public order and continental and intercontinental security. The Danube region will experience sustainable development through regional and not state-isolated projects, and thus the Danube is a security stabilizer for EU and non-EU member states, i.e. for EU-NATO.