Books on the Holocaust are not rare and this year alone two major works of popular scholarship have been published: Sarah Helm’s Ravensbrück: Life and Death in Hitler’s Concentration Camp for Women and Nikolaus Wachsmann’s KL: A History of the Nazi Concentration Camps. Yet for all of Wachsmann’s comprehensive authority and Helm’s attention to the long-overlooked position of women, it’s a third book that will perhaps have the deepest and longest-lasting impact, Timothy Snyder’s Black Earth: The Holocaust as History and Warning.

I knew of Snyder primarily through his astute analysis of the current conflict between Ukraine and Russia, and was intrigued that his new book wasn’t directly focused on that particular history—which is twisted and painful in all the ways a centuries-long conflict can be. But clearly the research he put into Black Earth has informed his current writing on Ukraine and it stands to reason that observing the unfolding events there over the past few years helped crystallize in his mind a key point he makes in the new book.

Snyder argues that, contrary to the belief that it was excessive state power that made the Holocaust possible, it was the collapse of state power in areas targeted by the Nazis that allowed it to happen. Where Nazi Germany and the U.S.S.R. dismantled existing states—such as Poland, Ukraine, and Lithuania—the lack of legal protections normally granted to citizens, especially ethnic minorities, was gone, resulting in an anarchic free-for-all of ethno-nationalist and collaborationist violence. Places where Jews retained legal protections as citizens did not see remotely the same level of violence as did those where Jews—as well as ethnic Poles and Ukrainians, among others—became stateless persons.

Snyder’s lucid, powerful book is directed squarely at Americans who believe that liberties are secured in the absence of governmental structures and he shows that it’s where people—particularly minorities—lose the protection of the state that atrocities occur.