Stephan Kieninger, a historian specializing in post-Cold War European security, discusses the ongoing impact of Cold War dynamics on the war in Ukraine. He highlights key negotiations involving Gorbachev, Yeltsin, and Putin, providing insights into NATO's expansion and Russia's desire for involvement in European security. The conversation explores critical misunderstandings that fueled tensions, the challenges of nuclear proliferation, and the inadequacies of security guarantees that failed to protect Ukraine. Kieninger's expertise sheds light on the complexities shaping today's geopolitical landscape.