The Russian invasion of Ukraine is raising questions left unresolved in the immediate aftermath of the Cold War, when President George Bush hoped to bequeath to his successors a peaceful, stable Europe whose nations would remain part of NATO. Among those questions is whether Russia would integrate with Europe, as the Soviet Union's former republics (such as the Baltic states) and satellite states (such as Poland) joined the Western military alliance. With its unprovoked attack on Ukraine, Russia has turned into a pariah state as President Vladimir Putin attempts to reverse his nation's diminished geopolitical status. In this episode, historian Jeffrey Engel discusses the causes of the first major war in Eastern Europe since 1945. It was not inevitable that relations between the West and the former Soviet Union would deteriorate, but certain problems – such as NATO's enlargement, Ukraine's pro-West revolution in 2014, and Putin's revanchist ideas – helped pave the road to war in 2022.