1. President Trump demanded that U.S. companies leave China after Beijing threatened new tariffs on $75 billion of American goods. He also said he would increase tariffs on all Chinese products.

In a series of angry tweets, Mr. Trump said American companies are “hereby ordered to immediately start looking for an alternative to China, including bringing our companies HOME and making your products in the USA.” It was not clear how the president planned to enforce his demands.

U.S. stocks fell more than 2 percent over Mr. Trump’s comments, highlighting the uncertainty stoked by the escalating trade war. The Federal Reserve chairman, Jerome Powell, said the central bank was limited in its ability to offset Mr. Trump’s trade policies. The president responded, “My only question is, who is our bigger enemy, Jay Powell or Chairman Xi?”