China’s ascent has led to its securitisation by its neighbouring states, particularly given its precarious maritime claims in the highly strategic Indo-Pacific basin. Such a development in the region has allowed India and Japan to forge closer strategic partnerships in Southeast Asia. This article utilizes securitisation theory to analyse the emerging Indo–Japanese nexus, wherein Japan’s increasing desecuritisation and India’s non-securitisation in Southeast Asia have allowed the region to emerge as a common strategic vantage point for Indo–Japanese interests to convene. The securitisation of China, coupled with India and Japan’s common interests in safeguarding the freedom of navigation and deterring unilateral changes to the status quo, contributes to the emergence of this nexus. Furthermore, the emerging nexus provides states of Southeast Asia a hedging option as China’s increasing assertion of its territorial claims. Japan’s Security Diamond policy and India’s Act/Look East policy will also be analysed to showcase the emergence of the Indo–Japanese nexus.