India, Aug. 6 -- This past week has seen a tectonic shift in Indo-US relations. Donald Trump first slapped a 25% tariff on Indian exports to the US and then topped it up with another 25% as a penalty for India buying Russian crude oil. While the first was shocking to a lot of people, the second is blatantly unfair. China buys more Russian crude than India, but Trump has not slapped any such penalty on China. As of now, tariffs on Indian exports to the US are 20 percentage points higher than on China's.

Where does this leave India and Indo-US relations? Are there larger lessons to be learnt? Answering this question requires an ideological clarity over and above merchandise trade. Here are three things which should matter.

Enemy's enemy i...