New Delhi, July 31 -- At the best of times, the World Economic Outlook (WEO) published by the International Monetary Fund (IMF) does not pose any risk to human vision with blinding new insights. Ditto for its three quarterly updates. But these are not the best of times. On Wednesday, US President Donald Trump used his very own microblog platform Truth Social to declare that "while India is our friend," imports from here would have to pay a tariff of 25%, plus a penalty for assorted US grievances, from 1 August.

Other countries have had to contend with such posts too. As the world's economies toss and turn amid choppy seas of trade uncertainty, policy watchers look to global bodies like the IMF for clues on how to reach calmer waters.

Al...