A Tariffs are a double-edged sword. The move to impose onerous tariffs on a foreign product benefits local manufacturers of a similar product as it means less competition at home. But it spells bad news for other local businesses that rely on the foreign product.

For example, Mr Trump's plan to impose a 25 per cent tariff on steel and 10 per cent on aluminium will help American steel and aluminium manufacturers, but it raises the costs of doing business for those relying on steel such as automakers, appliance manufacturers and construction companies.