Chennai, April 6 -- In 1947, the US led 23 nations into signing the General Agreement on Tariffs and Trade (GATT). The effort was to lower trade and tariff barriers among nations. Over the next 48 years, it took eight rounds of painstaking negotiations before GATT could evolve into the World Trade Organization (WTO) in 1995.

On 2 April, in a speech that lasted 48 minutes, US President Donald Trump effectively shredded this multilateral trading system and signalled a fundamental shift in US trade policy.

Speaking from the White House Rose Garden, Trump levied what he called reciprocal tariffs on all trading partners. The quantum of tariffs stunned the world. He announced a universal tariff of 10% on all imports. But countries which enjoy...