The manuscript contends that the strengthening of Australia's diplomatic relations with Southeast Asia can be attributed to the escalating threat posed by China's rise, the US's precarious role in the Asia-Pacific landscape, and the increasingly complex economic interconnections between the US, Australia, and Southeast Asia vis-à-vis China. Historically, the strategic alliance with the United States has been the cornerstone of Canberra's foreign policy framework. Nonetheless, Canberra's concerns about Washington's uncertain presence have grown as a result of the ongoing changes in US National Security Policy over the previous decade, from 2016 to 2025. In the long run, it can be argued that the dominant trajectory indicates Canberra's intention to strengthen its comprehensive strategic partnership with Southeast Asia, despite the increased complexity and fragmentation observed within Australia's multicultural society. While some analysts argue that Canberra's strategic alliance with the United States still predisposes it to prioritize the abandonment of Southeast Asia, there is a counterargument that Australia's strategic partnership with Washington is gradually dwindling after over 75 years of establishment and evolution. In light of the aforementioned circumstances, the manuscript advocates for Australia to recalibrate its domestic policies, particularly its ethnic policies concerning the Asian immigrant populace, and to leverage the existing networks of economic and social relationships with Southeast Asian nations, thus cultivating a framework of alliances among middle powers within the region, which would mitigate the risk of becoming ensnared in the strategic rivalry between the US and China in Southeast Asia.

This article analyzes South Korea’s new National Security Strategy (NSS) released in June 2023 under President Yoon Suk-yeol. The study situates the NSS in the context of rapidly changing regional and global geopolitics, examining the factors driving the emergence of this new strategy. The article primarily uses secondary document analysis methods to identify the content of the NSS; the research clarifies significant changes in South Korea’s approach to national, regional, and global security issues. The research results not only provide insights into South Korea’s national security strategy but also contribute to a better understanding of the geopolitical dynamics reshaping the regional order.