What is it exactly that India has that the US lacks? This author's answer seems to be simply: lots of people.
The assertion that the US and China will never go to war, nor India and China, is based on a naive assumption that the decision to go to war is always a rational one. We seem to forget: in 1914, trade was also a very global phenomenon. Although the levels of trade are today much higher, the importance of international trade to European economies at that time was not so different. Mark this: Britain was Germany's largest trading partner in 1914, and Germany was Britain's. France had high levels of foreign trade with Germany also. This did not stop Germany from going to war with both countries.
There is also the question of energy. The US has already gone to war for oil. China is making moves in central Asia. There may come a time, when both countries are struggling to meet their own energy needs (not to mention the rest of the world) that war may appear to be the only option to avoid energy (and therefore economic) starvation.
The US will do what it needs to do to meet its interests. India may prove to me more important in future, but an ironclad alliance is unlikely.
