Timothy Snyder, Richard C. Levin Professor of History at Yale, devotes this class to the 1940s as the decade of catastrophe for Ukraine, when Soviet and Nazi terror overlapped there more than anywhere else in Europe. He works through colonization, extermination, and ethnic cleansing as linked processes rather than separate horrors, tying them to how Polish, Russian, and Jewish self-understanding were themselves shaped by events on Ukrainian soil. Snyder pushes on the harder question underneath the history: what makes a nation exist at all, structures or actions or both, and why did Ukrainian statehood become so contested. He connects that argument to February 2022, using Ukrainians' resistance to the Russian invasion as evidence that the nation was already real before the war began. Part of his full Yale lecture course on Ukrainian history, delivered as a continuous classroom talk rather than an edited documentary.