The fourth edition of this well-established and popular text has been fully updated to take account of developments in the field of International Relations and recent world events. The authors provide systematic coverage of the classical concerns of International Relations theory - power, national interest, foreign policy and war - alongside analysis of the impact of globalization on security, governance and the world economy. A central concern throughout is to show how the theories the authors outline and assess can help make sense of the puzzle of current world events, from the rise of Russia and China, the downturn in the world economy and the changing role of America, to the challenges of identify politics and human rights.