Early Friday, China's Commerce Ministry announced tariffs on $3 billion worth of U.S. pork, aluminum scrap, apples, steel pipe, wine, ethanol, and other goods, saying President Trump's tariffs on imported steel and aluminum are "typical unilateralism and protectionism" and set a "very bad precedent." "China does not want to fight a trade war, but it is absolutely not afraid of a trade war," the Commerce Ministry said. "We are confident and capable of meeting any challenge. It is hoped that the U.S. side will be able to make a swift decision and not to drag bilateral economic and trade relations into danger."

China separately criticized Trump's announcement Thursday of tariffs on up to $60 billion in Chinese products, prompted by complaints of government-aided intellectual property theft. Beijing did not say how it would respond to that move, but the $3 billion in threatened tariffs announced Friday don't include items that would really hurt U.S. producers. "All the products on the list are small potatoes, and the real important ones are U.S. farm products like soybeans and sorghum," a government adviser in Beijing told The Wall Street Journal. "China is keeping its powder dry."

Global stock markets reflected the widespread unease at the looming trade war, with the Dow Jones Industrial Average closing down more than 700 points, or almost 3 percent, on Thursdays and Asian markets tumbling 3 percent in early trading Friday. A trade war with China would hurt U.S. consumers.

China did not say when its 25 percent tariff on U.S. pork and recycled aluminum and 15 percent tariff on the other goods might kick in, leaving time for negotiations. China exports only a small amount of steel and aluminum to the U.S. Late Thursday, the White House announced it will exempt allies like the EU, Brazil, South Korea, Mexico, Canada, and Australia from the steel and aluminum tariffs — accounting for two-thirds of U.S. steel imports and half of imported aluminum — until at least May 1. Peter Weber

On Wednesday, a new law in Poland took effect thataimed to force more than a third of the country's Supreme Court into early retirement, allowing the ruling right-wing Law and Justice Party to take control of the last part of the judiciary it hasn't already taken over. But many of the 27 targeted justices refused to step down, and Supreme Court president Malgorzata Gersdorf defiantly showed up to work, telling a crowd of supporters that she's "doing this to defend the rule of law and to testify to the truth about the line between the Constitution and the violation of the Constitution."

The government said it won't allow Gersdorf or other holdout judges to rule on any cases. Gersdorf, whose term is supposed to last until 2020, ended the day by saying she is going on "vacation," leaving Justice Josef Iwulski in charge. President Andrzej Duda had accepted Iwulski's petition to stay on the court — the law lowered the mandatory retirement age to 65 from 70; Iwulski is 66, Gersdorf is 65 — but Iwulski added to the confusion by saying "Duda neither appointed me, nor did he entrust any duties to me."

The Law and Justice Party, which has systematically taken control of the lower courts and Constitutional Court since winning power in 2015, says it's making the judiciary more responsive to the will of voters and ousting judges who were appointed when Poland was still communist. Tens of thousands of Poles protested the Supreme Court purge, including one of the men who wrote Poland's Constitution and Lech Walsea, a former president and the leader of the Solidarity movement that toppled Poland's communist government in the 1980s. "Whoever turns against the constitution, against the separation of powers, is a criminal,"Walsea said Wednesday afternoon. Walsea also told a radio program that if the government doesn't reverse course, "There will be a civil war. ... This is the path of civil war. I'd like to avoid it." Peter Weber