Recent crises have cast doubt on the legitimacy of technocratic power, yet its role in global economic governance remains poorly understood. Revisiting the collapse of Bretton Woods, we propose a dynamic theory of global monetary governance to explain how expanding central bank discretion can destabilise systems. While most studies attribute the postwar system’s failure to power-political struggles, institutional weaknesses, or shifting economic ideas, they overlook the policies designed to manage and stabilise it. Drawing on historical institutionalism, we show how coordination tensions between rule-bound and discretionary policymakers – and the mutually reinforcing adaptation risks they faced – produced responses that appeared stabilising in the short term but ultimately eroded long-run stability. New archival evidence from the International Monetary Fund, Bank for International Settlements, and Organisation for Economic Co-operation and Development reveals how tools like the London Gold Pool and currency swap lines extended central bank power, concealed macroeconomic imbalances, and crowded out political momentum for structural reform. As technocratic authority grew misaligned with political support and functional economic adjustment, it became a liability. In building this theory, we highlight the sociological, agent-level sources of instability rooted in technocratic policy discretion and interpersonal ties among central bankers – challenging the dominant view that technocratic actors are inherently superior in managing global economic policy.