Despite the divergence in Association of Southeast Asian Nations (ASEAN) countries’ initial responses to AUKUS, 1 year after the pronouncement of the tripartite security pact, ASEAN as a collective entity has already cautiously accepted AUKUS as a new reality. Regional states’ responses to AUKUS have been shaped by their concerns about the challenges to ASEAN centrality, possible negative impacts on regional stability, and their strategic approaches to relations with both the United States and China. As many policymakers and analysts have feared, it is indeed likely that AUKUS may spark a regional arms race in certain areas and on a limited scale and bring more challenges for regional stability. At the same time, there are also uncertainties regarding the implementation of AUKUS, which raise doubts about the balance of power and deterrence effects that this new security arrangement may be able to achieve. In the long run, more regional powers, including middle powers and smaller states, may gradually gravitate toward AUKUS in the form of partnership or ad hoc issue-based cooperation. In this sense, it is quite possible that AUKUS may provide a new and perhaps flexible mode of strategic realignment in the Indo-Pacific region. Amid growing US–China strategic rivalry, the strategic landscape in Indo-Pacific may become even more divisive and competitive.