This book examines the changing nature of global inequalities and efforts that are being made to move toward a more egalitarian world society. The contributors are world historical sociologists and geographers who place the contemporary issues of unequal power, wealth, and income in a global historical perspective. The geographers examine the roles of geopolitics and patterns of warfare in the historical development of the modern world-system, and the sociologists examine endeavors to improve the situations of poor peoples and nations and to engage the challenges of sustainability that are linked with global inequalities. This is cutting-edge research from engaged social scientists intended to help humanity deal with the challenges of global inequality in the 21st century.