Trump’s biggest mistake in the trade war with China

THE CONFIDENCE, even a certain complacency, that had developed around the likelihood of a successful conclusion to trade talks between China and the United States has given way to tension and uncertainty. On Sunday, President Trump, blaming Beijing for reneging on previously negotiated commitments, tweeted a threat to the effect that he would raise an existing 10 percent tariff on $200 billion worth of Chinese imports to 25 percent on Friday, with 25 percent tariffs on additional Chinese goods coming “shortly.”

News reports identify the Trump administration’s specific complaint as China’s...