Like many young idealists, Eric Greitens wanted to make a difference. During college and afterward, he traveled to the world's trouble spots, working in refugee camps, serving the sick and the poor on four continents, from Gaza to Croatia to Mother Teresa's home in Calcutta, among others. Yet he could not prevent violence or save anyone from becoming a refugee; he could only step in afterward and try to ease the damage.

So Eric joined the Navy SEALs and became an elite warrior. In a moving and inspiring memoir, told with genuine humility, Eric offers something new in the history of military memoirs: a warrior who wanted to be strong to be good, only to discover that he had to be good to be strong. Throughout his SEAL training and deployments in Kenya, Thailand, Afghanistan, and Iraq, the lessons of his humanitarian work bore fruit. The result is a lesson for us all: the heart and fist together are more powerful than either one alone.