The end of the Cold War between the United States and the former Soviet Union reassured people around the world who had lived in fear of a nuclear confrontation between the superpowers. Yet the early euphoria over "peace dividends" and a "new world order" was premature. Conflicts within and between nation-states are springing up around the globe, challenging world leaders and ordinary citizens to find peaceful means for national, group, and individual self-determination.

In this book of specially commissioned essays, twenty world leaders assess the possibilities and perils of the...