This is the least surprising development in the days since Defense Secretary James Mattis announced his resignation from the Trump administration.

Donald Trump has told the defense boss to hit the road at the end of next week; don’t bother waiting until the end of February.

The president appears to be angered over Mattis’ rebuke of him in his letter of resignation. It’s an unprecedented dismantling of the president’s approach to foreign and defense policy. What’s more, the letter lacks a single word of appreciation for the service Mattis rendered to the president himself, although Mattis does restate his pride in serving the men and women in uniform.

Accordingly, Trump decided to give Mattis an extra push out the door. If you think about it, that is an understandable reaction from the president, given the tone and tenor of the letter that Mattis delivered in announcing his resignation.

It does not diminish or degrade the essence of the concerns that Mattis raised in declaring his intention to depart from his post as defense secretary.

So now the Trump administration will have an acting defense secretary, Patrick Shanahan, to go along with an acting White House chief of staff, an acting Environmental Protection Agency administrator, an acting interior secretary, an acting attorney general and,  um, no ambassador to the United Nations.

This is not a “fine-tuned machine.”