The president’s trade assault, which makes no distinction between ally and adversary, is an assertion of U.S. dominance with significant risks.

President Donald Trump said the sweeping tariffs that he has imposed on Mexico, Canada and China may cause "short term" pain for Americans as global markets reflected concerns the levies could undermine growth and reignite inflation.

WASHINGTON— President Donald Trump on Saturday signed an order to impose stiff tariffs on imports from Mexico, Canada and China, drawing swift retaliation and an undeniable sense of betrayal from the country's North American neighbors as a trade war erupted among the longtime allies.