Over the past decade, China, India, and the United States have all increased their involvement in energy infrastructure development in South Asia. In this process, tripartite competition and cooperation are influenced not only by market factors such as the supply and demand of energy infrastructure in South Asia, but also by strategic interactions among China, India, and the United States at both the international and regional levels. In addition to market-based approaches, securitization tactics have emerged as a significant means of influencing the competitive and cooperative interactions among the three parties, particularly evident in the adept use of such tactics by India and the United States to gain an edge in their competition with China. Small and medium-sized countries in the region have passively or actively joined in the process of securitizing energy infrastructure, making the competition and cooperation among all parties over South Asian energy infrastructure even more complex. This study suggests that the increasing security of energy infrastructure in South Asia is transforming the interaction logic, strategic choices, and cooperation space between China, India, and the United States around this issue. In the long term, placing too much emphasis on security will further exacerbate distrust and competition among the involved parties, potentially leading to an increase in security challenges and causing related projects to stall.