It is hard to imagine a sadder group of people than the children of Americans who spied for the Soviet Union. I am thinking of the two sons of Julius and Ethel Rosenberg, the son of Alger Hiss, and now Harry Dexter White’s two daughters, who in a recent letter to the New York Times Book Review rebuke a reviewer for referring to their father, a high-ranking Treasury official under Roosevelt and Truman, as a Soviet agent. What a tragedy the end of the Cold War has been for the kids and grandkids of the spies. How do they talk...