Due to Southeast Asia's geopolitical, economic, and commercial significance, world powers have focused on this region. China and India, the two neighboring nations of Southeast Asia, both with aspirations to become the dominating force in the Indo-Pacific region, have been employing all means to draw Southeast Asia into their sphere of influence. Controlling Southeast Asia would confer immense strategic gains on both nations. The goal of this study is to assess the policy of India and China toward Southeast Asia utilizing pertinent data and documents, official comments from the respective governments, and the research of Vietnamese and foreign researchers. The analysis reveals that India and China seek benefits by promoting close ties with Southeast Asia, but their methods for achieving this objective are distinct. Suppose India employs flexible diplomatic measures to develop its good relations with Southeast Asia. In that case, China has the upper hand when pursuing a diplomatic strategy that is both flexible and assertive to advance its objectives, particularly in East Sea-related problems. This provides Southeast Asia/ASEAN with difficult choices and decisions about India and China to balance their respective interests and, more significantly, to maintain ASEAN's central position in regional and international concerns.