“Tariffs are making our Country Strong and Rich,” Mr Trump crowed on social media on August 11th. They also, however, guarantee that America will become steadily less important to its trading partners. That is one predictable consequence of an unpredictable presidency. ■

After months of delay, higher tariffs that President Donald Trump had vowed to impose on goods imported from dozens of countries went into effect on Aug. 7. Trump has made a series of false and misleading statements to justify his new tariff policies.