China Meets the U.S. to Discuss Fentanyl, But the Détente Has Limits

China and the United States are back at the negotiating table. Whether they can agree on much is another matter. In Bangkok, China’s top diplomat last week discussed North Korea and Iran with President Biden’s national security adviser. Days later, in Beijing, officials restarted long-stalled talks on curbing the flow of fentanyl to the United States. And the White House says Mr. Biden plans to speak by phone with China’s leader, Xi Jinping, in the spring. The developments point to a tentative détente struck by Mr. Biden and Mr. Xi…