Buying arms from big trading partners is a good idea
From the geopolitical perspective, the Boeing P8I “Poseidons” that India has contracted to purchase are very good deal. India should ideally purchase military equipment from countries with whom it has broad and deep trading relationships. The current situation is quite the opposite: India has next to no non-military trade with Russia, and a little with Israel—the two largest military equipment suppliers. This gives them undue strategic and commercial leverage, which Russia has been exploiting to its advantage.
So India must deepen trade and investment with Russia and Israel. And buy arms from the United States, with whom it has wide-ranging economic ties.
Another reason for increasing the American share in India’s equipment mix is operational interoperability. India must develop the capability to interoperate with US and its allies as it will become necessary in a variety of future conflicts. This does not mean buying whatever is on offer—for instance, while augmenting amphibious capacity with landing ship tanks is a good idea, purchasing a huge aircraft carrier is not.