This book offers a comprehensive analysis of the unfolding US–EU–Russia rivalry in the Euro-Atlantic from 1992 to 2025. Drawing on a novel theory termed neo-offensive realism, it examines why, where, how and whether this competition has intensified in the Euro-Atlantic region, particularly in the aftermath of the Russo–Ukrainian war. It advances a cross-level, multi-actor framework, demonstrating how system- and unit-level forces interact to shape US–EU–Russia rivalry across a diverse range of states and quasi-states in the Euro-Atlantic.