This Foreign Affairs article explains
INDIA GOES IT ALONE
While U.S.-Indian security cooperation has enjoyed marked success, the larger defense partnership still faces important challenges. Both nations seek to leverage their deepening ties to limit China’s assertiveness, but there is still a significant divide in how they aim to accomplish that purpose.
The U.S. goal in military-to-military cooperation is interoperability: the Pentagon wants to be able to integrate a foreign military in combined operations as part of coalition warfare. India, however, rejects the idea that its armed forces will participate in any combined military operation outside of a umbrella. Consequently, it has resisted investing in meaningful operational integration, especially with the U.S. armed forces, because it fears jeopardizing its political autonomy or signaling a shift toward a tight political alignment with Washington. As a result, the bilateral military exercises may improve the tactical proficiency of the units involved but do not expand interoperability to the level that would be required in major combined operations against a capable adversary.
India’s view of military cooperation, which emphasizes nurturing diversified international ties, represents a further challenge. India treats military exercises more as political symbols than investments in increasing operational proficiency and, as a result, practices with numerous partners at varying levels of sophistication. On the other hand, the United States emphasizes relatively intense military exercises with a smaller set of counterparts.
But on the most burdensome challenge facing Washington in the Indo-Pacific—securing meaningful military contributions to defeat any potential Chinese aggression—India will likely refuse to play a role in situations where its own security is not directly threatened. In such circumstances, New Delhi may at best offer tacit support.
Consequently, India’s security partnership with the United States will remain fundamentally asymmetrical for a long time to come. New Delhi desires American support in its own confrontation with China while at the same time intending to shy away from any U.S.-China confrontation that does not directly affect its own equities. Should a major conflict between Washington and Beijing erupt in East Asia or the South China Sea, India would certainly want the United States to prevail. But it is unlikely to embroil itself in the fight.