The Quad as a Security Actor Tanvi Madan (bio) When the Quad briefly emerged in 2007–8 among Australia, India, Japan, and the United States, this minilateral was referred to as the Quadrilateral Security Dialogue. Although some member states occasionally still use that term—often casually—it has been eschewed as a formal designation. Indeed, Quad members have gone out of their way to highlight a softer purpose rather than a security framing for the coalition. They have emphasized the idea of the group as a solutions provider for regional problems, including the Covid-19 crisis and climate change, while simultaneously officials have either denied or downplayed the grouping's security dimension.1 In September 2021, for instance, a senior U.S. official emphasized that the Quad "is not a regional security organization." The official further added that "there is not a military dimension…or security dimension" to the grouping.2 However, while the Quad is not a regional security organization or alliance and does not involve formal security commitments or treaty obligations, it does have security and even some military dimensions. This element may not be evident in members' public statements, but as this essay argues, it is a key component of the Quad and the cooperation between its members. The Quad's resurrection lay in the need to respond to a security challenge—a more assertive and powerful China. This was not the only driver, but without it, the Quad was neither necessary nor possible. The member states' desire to respond to this challenge by shaping a [End Page 49] favorable balance of power and building resilience in the region has led to several lines of effort, including in the defense and security domains. Among other elements, these interactions have involved building on a relatively low base of member-state interconnection in these sectors, particularly with India. Members' engagement in these realms has been evident in three areas: (1) security consultations and activities via the Quad, (2) sub-Quad activities, involving the deepening of ties between the Quad partners bilaterally and trilaterally, and (3) supra-Quad activities, consisting of member-state cooperation with other like-minded partners. The China Driver The Quad re-emerged in 2017 in the context of Beijing's increasing assertiveness, particularly in the Indo-Pacific. Each of the member states had growing concerns about China's intentions, expanding capabilities, and footprint, as well as the region's vulnerabilities. In addition, it was neither feasible nor desirable for strategic, economic, or political reasons for any of these countries to tackle the China challenge alone. The regional security architecture was also underdeveloped and unequal to the task, while U.S. bilateral alliances and regional partnerships were insufficient to deal with the challenge, as were international organizations. Moreover, some of the United States' allies did not share either the same concerns or its risk tolerance toward China—and those that did were linked through a hub-and-spoke alliance system that connected each ally with the United States but not closely with one other. Finally, although it was a like-minded ally, Japan, for largely historical reasons, had been a reticent and limited security actor, while India, a key country that also shared concerns about China—and was willing to do something about the challenge—stood outside the U.S. alliance system. These willing and capable countries felt a need to broaden and deepen their consultation, coordination, and cooperation to help address the challenge that China posed. For Australia, Japan, and the United States, a collective security solution might have been the answer, but not for non-ally India. The next best option, to tweak Charlie Lyons Jones's framing, was collaborative security.3 Enter the Quad. [End Page 50] Since 2017, with a shared (though not identical) threat assessment in the region vis-à-vis greater Chinese assertiveness, several of the Quad's activities seem to be devised around two lines of effort: shaping a favorable balance of power so that a unipolar, China-dominant Asia does not emerge, and building resilience in the region. Both have involved an element of bolstering individual member capacity, their collective capacity as a minilateral grouping, and regional capacity to detect...