When Lieutenant Commander Heidi Kraft's twin son and daughter were fifteen months old, she was deployed to Iraq. A clinical psychologist in the US Navy, Kraft's job was to uncover the wounds of war that a surgeon would never see. She put away thoughts of her children back home, acclimated to the sound of incoming rockets, and learned how to listen to the most traumatic stories a war zone has to offer.
One of the toughest lessons of her deployment was perfectly articulated by the TV show M*A*S*H: "There are two rules of war. Rule number one is that young men die. Rule number two is that...