Like many young idealists, Eric Greitens wanted to make a difference. Throughout college and after, he traveled to the world's trouble spots, working in refugee camps and serving the sick and the poor on four continents, from Gaza to Croatia to Mother Teresa's home in Calcutta, among others. Yet when innocent civilians were threatened with harm, there was nothing he could do but step in afterward and try to ease the suffering. He became a Rhodes Scholar to study the history of humanitarianism, in search of a better way, but all the theory in the world could not get past the fundamental problem: when an army invades, the weak need to be protected. So he joined the Navy SEALs and became one of the world's elite warriors. As an officer, he led his men through the unforgettable soul-testing of SEAL training, culminating in Hell Week recounted in these pages with remarkable detail and went on to deployments in Kenya, Thailand, Afghanistan, and Iraq, where he faced harrowing encounters and brutal militia attacks. Yet even when he wore heavy armor and wielded some of the deadliest combat arms, the lessons of his humanitarian work bore fruit. At the heart of Eric's powerful story lies a paradox: sometimes you have to be strong to do good, but you also have to do good to be strong. The heart and fist together are more powerful than either one alone.