After the 2008 Global Financial Crisis (GFC), the Asia Pacific witnessed a new wave of multilateral institutional efforts by non-ASEAN states, such as the United States, China, Japan, Australia, and South Korea. I call this phenomenon “multilateralism 2.0” in order to differentiate it from “multilateralism 1.0” of the 1990s mainly led by ASEAN. Why did these non-ASEAN states engage in “multilateralism 2.0” and why do they choose different institutional strategies? This project answers these two questions by integrating institutional balancing theory from international relations and role theory from foreign policy analysis. I argue that “contested multilateralism 2.0” is a result of institutional balancing among major states under the conditions of high strategic uncertainty and high economic interdependence after the GFC. However, a state’s role conception shapes its specific institutional balancing strategy during an order transition period. An order defender, like the United States, is more likely to adopt exclusive institutional balancing to exclude other states from its dominated institutions. An order challenger, such as China, will choose both inclusive and exclusive institutional balancing to maximize its own power and legitimacy in a new international order. As a kingmaker, a proactive second-tier state is more likely to pick an inter-institutional balancing strategy and initiate new institutions to compete for influence with existing institutions. An institutionalized order transition might be more peaceful than widely perceived.