SHANGHAI — President Trump said on Sunday that the United States could consider stopping all trade with countries doing business in North Korea, in a move that could spell economic catastrophe for the pugnacious country.
One problem: It would mean economic disaster for the United States as well.
Despite years of economic sanctions and international condemnation, North Korea still conducts modest trade with a host of United States allies, including Brazil, Germany and Mexico.
But the North’s biggest partner by far is China, which accounts for about four-fifths of its trade and helps the country with its fuel, food and machinery needs….