As one-half of the latest edition of Immanuel Wallerstein's Political Economy of the World System series, this collection offers cutting-edge theoretical directions to explain the structural crises of the 21st century world system. Contributors argue that the capitalist world system has reached a critical bifurcation point, a short period which will be characterized by a sudden shift in the long-term structural forces that have created and sustained the world as we know it. Writers challenge conventional thinking about the most significant structural crises that face the 21st century world system, including terrorism, debt, the growth of megacities as global actors, the emergence of a powerful transnational capitalist class, and the world ecological crisis.