The changing geopolitical context compels middle powers to act. Countries have responded by forming explicit alliances, building upon hedging strategies or altering their leanings from one great power to another. The need for collective action is more urgent than ever to deal with emerging regional and global challenges. This issue of East Asia Forum Quarterly looks at middle powers and the range of priorities they have. Some are focused on their domestic priorities while others are more eager to shape the political, economic and security dimensions in the region. Our contributors offer a variety of perspectives on the challenges that middle powers face and identify the call of middle-power vision in defending the rules-based order.