The consensus was that Darroch lost his job for telling the truth.
But truth-telling is only part of an ambassador’s job — a part that depends very much on that truth being delivered in the proper time and the proper place to the proper people. Darroch was right to offer his candid assessment of Trump to his bosses. That’s where the dissemination of his honesty should have stopped. It is not his fault those assessments were leaked. It is not surprising, however, that when the leaks happened, they proved fatal to Darroch’s employment.
Ambassadors, after all, are supposed to represent the interests of their country. It’s a job that can involve flattery, cajoling, negotiating, wheedling, and all the other tools of persuasion. It is also a job that involves an unusual amount of discretion — and complete honesty only rarely. It is difficult to make the leaders of other countries amenable to your nation’s interests if those leaders know you have been calling them “clumsy” and “inept” behind their backs.