I was fifty-nine when I began serving as U.S. secretary of state. I thought by then that I knew all there was to know about my past, who "my people" were, and the history of my native land. I was sure enough that I did not see a need to ask questions. Others might be insecure about their identities; I was not and never had been. I knew.

Only I didn’t. I had no idea that my family heritage was Jewish or that more than twenty of my relatives had died in the Holocaust. I had been brought up to believe in a history of my Czechoslovak homeland that was less tangled and more straightforward than the reality. I had much still to learn about the complex moral choices that my parents and others in their generation had been called on to make -- choices that were still...