Early in my days as a freelance journalist, I was on the lookout for a book subject themed to some sort of big human drama. I found that theme one morning on a path along a rosemary-scented Jerusalem hillside—the site of Israel’s Holocaust memorial, Yad Vashem. The path was flanked by orderly rows of carob trees, their branches hung with the long brown pods, the very kind, probably, that had sustained John the Baptist in the wilderness.