New Delhi, Feb. 11 -- President Donald Trump promised a trade war and has fired the first shots. The US leader has chosen to use cannon balls rather than mere bullets, imposing a 25% tariff on goods imported from Mexico and Canada and 10% on imports from China (he had threatened 60% before assuming office).

On 3 February, both Canada and Mexico were given a 30-day reprieve, with concessions extracted from them-the beefing up of border patrols to prevent ingress of fentanyl and illegal immigrants. While both Canada and Mexico had threatened retaliatory tariffs, they too have deferred action in the wake of Trump's decision to temporarily suspend tariffs on them.

In the case of China, Trump has delayed the US crackdown on a loophole that r...