This article primarily focuses on how the increasing US–China competing strategies in Asia-Pacific affect the policies of South Asian rivals India and Pakistan when, on the one hand, the US as part of its offshore balancing grand strategy has been increasing its strategic partnership with India through the transfer of emerging technologies in terms of military modernization process, and on the other hand, China and Pakistan have improved their geo-economic and geostrategic partnership as part of the Chinese grand strategy via the Belt and Road Initiative while enabling Pakistan to produce effective countermeasures against its potential adversary. The article presumes that, in doing so, such competing strategies frame a quadrangle setting comprising of US and India to deter and contain China on the one hand and China and Pakistan to produce countermeasures and try to create a balance to potentially prevent the risk of conflict in South Asia out of such competing strategies at the quadrangle order conceived here. However, in fact, neither the US nor rising China would desire such a possibility of conflict otherwise unintendedly occurring from the intense US–China competing strategies while affecting the policies of the South Asian rivals. The article concludes that the shaping of this quadrangle framework may bring both opportunities and challenges for the South Asian rivals. It also concludes that the more intense the competition between the US and China becomes, the more intense its implications could be on the South Asian rivals, while the reduced tension between China and the US, although unlikely, would have reduced pressure on India and Pakistan relations as well.