Ukraine is again—since its annexation of Crimea in February 2014 and the ongoing war in the Donbass—the stage of the largest crisis in Europe since the end of the Cold War. When it comes to understanding the resolution and prevention of complex hybrid conflicts, theories in international relations are trapped in their state-centered perspectives. Meanwhile, the role of the individual actor, alone or organized, often remains underestimated as political and moral agent. In this book, Marc Raphael Dietrich sheds light on a critical yet politically practicable notion of cosmopolitanism which centers on the individual and is framed by a set of universal principles, thus providing valuable alternative insights on the Crimea and Donbas conflict.