Stock markets declined after the president’s early-morning threats of 25 percent import taxes on iPhones and 50 percent on goods from Europe.

Is now a good time to upgrade your iPhone? Not since the lights nearly went out on TikTok have U.S. consumers been so rattled. That might be an overstatement, but President Donald Trump has shown he has the power to save or cause trouble for companies that don’t adhere to his political agenda — and Apple is no exception.