For a guy who has spent his life delivering messages — as a businessman, reality TV star, presidential candidate and now president — President Trump is doing an abysmal job explaining his view of the world and America’s place in it. Normally, that would increase the importance of Secretary of State Rex Tillerson. But if Mr. Trump’s messages are confusing, Mr. Tillerson’s are almost nonexistent.

Secretary of state has traditionally been seen as the premier cabinet position. But Mr. Tillerson has shown little interest in asserting a public role for himself or his department. Instead, he has been avoiding public accountability on matters of war, peace and pretty much everything else. That includes pressing issues like the administration’s plans for pumping up the fight against the Islamic State. Mr. Tillerson risks diminishing his position, that of his department and possibly the influence of his successors.

For instance, after Mr. Trump signed his Muslim ban 2.0 on Monday, Mr. Tillerson and his counterparts at Justice and Homeland Security held a press event and dutifully read out statements about the new order. But they refused to answer questions, making it clear they saw reporters as mere pawns in their P.R. tableau. And at Mr. Tillerson’s photo op with the Ukrainian foreign minister the next day, he ignored Andrea Mitchell, the veteran NBC correspondent, who was firmly ushered out of the room by State Department employees when she tried to question the secretary about China and North Korea.

It’s not that previous secretaries didn’t sometimes duck questions. But Mr. Tillerson has been shockingly inaccessible since he was sworn in last month. On top of questionless photo ops, there have been no news conferences and no Sunday talk show appearances. Compounding the problem, Mr. Tillerson silenced the State Department’s institutional voice for six weeks by suspending the press briefing, which had been conducted by a spokesperson on a regular basis (usually daily) for decades. The briefings resumed Tuesday after an internal debate over their value; plans are to hold two public briefings and two conference calls per week.