This paper develops a theory of strategic inclusion to explain why a middle power may actively facilitate the entry of a state with uncertain intentions into a multilateral governance regime that is strategically important to its own interests. We argue that middle powers are more likely to support such inclusion when the prospective member can help address a legitimacy crisis confronting the regime, when policymakers do not perceive the state through a worst-case-scenario lens, and when its membership is unlikely to disrupt the existing status quo or intensify power competition within the relevant issue area. Under these conditions, inclusion becomes a pragmatic strategy through which middle powers strengthen multilateral institutions while advancing their own national interests.
We examine this argument through Australia’s support for China’s entry into the Antarctic Treaty System (ATS) during the late 1970s and early 1980s. At the time, the ATS faced growing challenges to its legitimacy from both consultative and non-consultative parties, raising concerns about the regime’s long-term stability. Meanwhile, China’s reform and opening-up policies, expanding diplomatic engagement with Western democracies, and growing participation in international organisations encouraged Australian policymakers to view Beijing as a state whose future trajectory remained uncertain but not overtly threatening. Rather than treating China as a potential challenger to the Antarctic order, Canberra identified strategic opportunities in engaging Beijing and incorporating it into the existing governance framework.
Drawing on archival evidence, the paper shows that Australian policymakers viewed China’s participation as a means of reinforcing the legitimacy and durability of the ATS while safeguarding Australia’s own Antarctic interests. Although Canberra adopted a cautious approach that avoided excessive encouragement of Chinese ambitions, it consistently concluded that cooperation with Beijing would best serve Australia’s broader strategic objectives. The case demonstrates how strategic inclusion can help explain middle-power behaviour toward states of uncertain intentions and highlights the role of middle powers in shaping regime membership, managing uncertainty, and sustaining international order during periods of geopolitical change.
