The amalgam of security-related issues that Japan faces in the region of East Asia, such as tensions due to the rise of China and inter-state relations, has become increasingly problematic for Japan as it navigates its foreign policies. Under such convoluted conditions, Japan announced the concept of Official Security Assistance (OSA) in 2022. While OSA is yet to be fully understood, this study aims to comprehend the intentions behind Japan’s new military aid by comparing its conceptualization with the U.S. Foreign Military Financing as a reference point. The research compares Japan’s OSA and the U.S.’ Foreign Military Financing. Specifically, the study focuses on two points: (1) the presence of threats to the countries and (2) the role of military aid as an alternative strategy in dealing with security conditions. Through this juxtaposition, we assert that the intention of military aid acted as an alternative strategy by avoiding certain risks and enhancing and diversifying the means of deterrence against a potential threat. Moreover, the study seeks to analyze the trajectory of military aid provided by the U.S. and the challenges and outcomes OSA may experience. As Japan emphasizes its Indo-Pacific strategy and its resurgence as an active actor in the East Asian security realm, this new concept may prove to be a significant turning point.