In figuring out why the U.S. tariff shock hasn't sent the economy or financial world into a tailspin, Britain's exit from the European Union trade bloc provides something of a playbook - and without a particularly happy ending.

President Donald Trump signed an executive order Thursday, slapping tariffs on most of America's trading partners set to take effect next week.

The tariffs U.S. President Donald Trump imposed last week on dozens of countries are expected to remain in effect rather than be reduced during ongoing trade negotiations, U.S. Trade Representative Jamieson Greer said Sunday.