Mr. Tillerson has skipped every opportunity to define his views or give guidance to American diplomats abroad, limiting himself to terse, scripted statements, taking no questions from reporters and offering no public protest when the White House proposed cutting the State Department budget by 37 percent without first consulting him.

He suffered in silence, State Department officials said, when President Trump called, in a matter-of-fact way, to reject Mr. Tillerson’s choice for deputy secretary of state. He has been absent from the White House meetings with key world leaders, and when the State Department issued its annual report on human rights — usually a major moment for the United States to stand up against repression around the world — he skipped the announcement…

On Tuesday, Mr. Tillerson will leave for his first truly fraught diplomatic mission: a trip to Japan, South Korea and China, at a moment when open conflict with North Korea is a growing possibility, and when the administration is planning Mr. Trump’s first meeting with President Xi Jinping of China. The trip is so vital that the “principals” committee of the National Security Council is set to convene on Monday to discuss the North Korean threat and how to deal with China, so that Mr. Tillerson speaks from a consensus strategy.

But do not expect to hear much about that strategy from the secretary before he arrives in Asia: The State Department has told reporters that they cannot ride on the plane. The decision appears to be unprecedented for a major diplomatic trip — even four decades ago, when Mr. Kissinger was conducting shuttle diplomacy in the Middle East and opening up China, he was delivering spin to reporters on the plane and offering up diplomatic tutorials.