"Excuse me, are you Jewish?" With these words, the relentlessly cheerful, ideologically driven emissaries of Chabad-Lubavitch approach perfect strangers on street corners throughout the world in their ongoing efforts to persuade their fellow Jews to live religiously observant lives. In The Rebbe's Army, award-winning journalist Sue Fishkoff gives us the first behind-the-scenes look at this small Brooklyn-based group of Hasidim and the extraordinary...