The president’s plan for reciprocal tariffs sounds good in theory. But there was a reason the United States abandoned the approach a century ago. The gains would be few and the costs enormous.

Trump's official memorandum outlining the policy said the administration's reciprocal tariffs might also be designed to offset so called "non-tariff barriers" to trade such as other countries' regulations, domestic subsidies, currency values and Value Added Taxes (VAT).

President Donald Trump is taking a blowtorch to the rules that have governed world trade for decades. The “reciprocal’’ tariffs that he announced Thursday are likely to create chaos for global businesses and conflict with America’s allies and adversaries alike.