“Revisionism” is supposed to mean a rejection of the existing international order. Yet the meaning of international order has been underdeveloped in current research. This chapter delineates this idea, relying on the English school’s writings. It distinguishes the primary and secondary institutions of international order and introduces a collection of indicators to track and measure Chinese and US commitment to two aspects of international order: one that is norm-based and the other that is rule- or institution-based. These indicators encompass these countries’ official pronouncements, their involvement in wars and militarized disputes, their engagement in international political economy, and their participation in international organizations and multilateral treaties. The evidence shows that, contrary to customary depiction, the United States has become more revisionist over time and according to some measures, more so than China.