International political economy (IPE) emerged as a heterodox approach to international studies during the 1970s as rising oil prices and the breakdown of the Bretton Woods international monetary system alerted Anglo‐Saxon academic opinion to the importance, contingency, and weakness of the economic foundations of world order. Traditional study of international relations was held to have placed excessive emphasis on law, politics, and diplomatic history. Conversely modern economics was accused of abstraction and inaccessibility. Drawing heavily on historical sociology, intellectual history, and economic history, IPE instead proposed a fusion of economic and political analysis. In addition, many adherents—both Marxist and liberal—protested against the reliance of Western social science on the territorial state as the unit of analysis, preferring a holistic approach to world politics. By the 1990s IPE had largely succeeded in transforming the old orthodoxy yet stood in some danger of succumbing to respectability as a tolerated subfield of international relations. See also political economy; politics and economics.