Josh Rogin in The Washington Post:

Secretary of State Rex Tillerson’s job running the State Department just got considerably more difficult. The entire senior level of management officials resigned Wednesday, part of an ongoing mass exodus of senior Foreign Service officers who don’t want to stick around for the Trump era.

Undersecretary Patrick Kennedy and three of his top officials. It’s not clear if they resigned on their own, or if they were pushed out.

“It’s the single biggest simultaneous departure of institutional memory that anyone can remember, and that’s incredibly difficult to replicate,” said David Wade, who served as State Department chief of staff under Secretary of State John Kerry. “Department expertise in security, management, administrative and consular positions in particular are very difficult to replicate and particularly difficult to find in the private sector.”

Regardless of whether they chose to leave or not, it’s a statement on the Trump administration. Either these career officers couldn’t bear to work under Trump (and he was unable to convince them otherwise), or Trump decided he didn’t want (or need?) their expertise.

Either way, their departure leaves the State Department worse off, and U.S. diplomats less safe.