WASHINGTON — 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.

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.

President Trump has announced reciprocal tariffs targeting countries like China and India, among others. The move challenges WTO principles and has sparked discussions on potential retaliatory measures.