In this undergraduate thesis will explain why the United States chose India as its major defense partner. In the Asia Pasifik region cooperation with US allied countries is considered not able to offset the rise of China. To maintain its hegemony in this region, the US feels the need to establish cooperation with the state that is strong in rivaling China. Large military capability, geographical proximity of China to US allies and nuclear ownership will pose a threat to US hegemony. However, India also has these factors, therefore the selection of India as US’s major defence partner is very appropriate. The United States has previously cooperated with Japan, South Korea, the Philippines and other countries in Asia but is considered unable to control the rise of China. The author uses qualitative methods using descriptive analysis methods. While the data collection technique is the Library Research Technique. The theory used is the theory of Balance of Threat and supported by the Rational Choice Model. The result of this research is that America's interest in choosing India as its main defense partner is to offset the rise and influence of China in the military aspect.