The author has three goals in writing this book. The first is to explore large-group identity such as ethnic identity, diplomacy, political propaganda, terrorism and the role of leaders in international affairs. The second goal is to describe societal and political responses to trauma at the hands of the Other, large-group mourning, and the appearance of the history of ancestors and its consequences. The third goal is to expand theories of large-group psychology in its own right and define concepts illustrating what happens when tens of thousands or millions of people share similar psychological journeys. The author is a psychoanalyst who has been involved in unofficial diplomacy for thirty-five years. His interdisciplinary team has brought enemy representatives, such as Israelis and Arabs, Russians and Estonians, Georgians and South Ossetians, together for dialogue. He has spent time in refugee camps and met many world leaders.