WASHINGTON — On the first Friday in May, Foreign Affairs Day, the staff gathers in the flag-bedecked C Street lobby of the State Department beside the memorial plaques for the 248 members of foreign affairs agencies who have lost their lives in the line of duty. A moment of silence is observed. As president of the American Foreign Service Association, Barbara Stephenson helps organize the annual event. This year, she was set to enter a delegates’ lounge to brief Secretary of State Rex Tillerson on its choreography before appearing alongside him. Instead, she told me, she was shoved out of the room.

Stephenson, a former ambassador to Panama, is not used to being manhandled at the State Department she has served with distinction for more than three decades. She had been inclined to give Tillerson the benefit of the doubt. Transitions between administrations are seldom smooth, and Tillerson is a Washington neophyte, unversed in diplomacy, an oilman trying to build a relationship with an erratic boss, President Trump.

Still, that shove captured the rudeness and remoteness that have undermined trust at Foggy Bottom. Stephenson began to understand the many distressed people coming to her “asking if their service is still valued.” The lack of communication between the secretary and the rest of the building has been deeply disturbing.

An exodus is underway. Those who have departed include Nancy McEldowney, the director of the Foreign Service Institute until she retired last month, who described to me “a toxic, troubled environment and organization”; Dana Shell Smith, the former ambassador to Qatar, who said what was most striking was the “complete and utter disdain for our expertise”; and Jake Walles, a former ambassador to Tunisia with some 35 years of experience. “There’s just a slow unraveling of the institution,” he told me.