They come from every corner of the country—investment bankers, farmers, computer geeks, jazz drummers, botany professors, car mechanics—leaving their jobs and their families. They put on uniforms that are invariably too tight or too baggy, sign out their gear and guns. Then, scrambling onto military vehicles, 70,000 reservists—women and men—join the young conscripts of what is proportionally the world's largest citizen army. They all know that some of them will return maimed or not at all. And yet, without hesitation or (for the most part) complaint, proudly responding to the call-up, Israelis stand ready to defend their...