The dream of President Trump being nannied by so-called "adults in the room" must be abandoned for good.

It is not clear to me that this is entirely a bad thing. In the case of James Mattis, who resigned as secretary of defense on Thursday, I think the case might be argued otherwise. Let's consider his two years helming the Defense Department.

Why did Mattis accept the job in the first place? In the United States, Cabinet officials serve at the pleasure of the president. They are not unofficial agents of some private policy agenda or a consensus to which the commander in chief does not subscribe. If his letter of resignation tells us anything — beneath all the PowerPoint-ese — it is that Mattis was fundamentally unsuited for his position. If he were really so appalled by Trump's rhetoric about our mighty NATO allies — Slovenia, for example, with its 6,700 active duty servicemen — he had no business signing up to help Trump remake the alliance.

Mattis, like most members of our foreign policy establishment, is delusional about Europe. The United States is an empire, not a republic. Nor are the NATO member states, in any meaningful sense, our allies. They are American vassal states and have been since the end of the Second World War. Their citizens have casually enjoyed a standard of living unknown to residents of the imperial capital, whose own elected officials cannot even agree that they enjoy a right to health care. Their leaders scold us for not supporting their mad schemes of improvement, the same ones that lead their own people to burn cars in the streets. Dismissing these polite fictions does not mean an end to America's role as guarantor of European peace and security — but rather an acknowledgement that the relationship is paternal rather than fraternal. If we are going to have an empire, it is going to be one ruled from Washington, not Brussels. Trump may not be able to spot Montenegro on a map, but he understands this reality.

Trump realizes something else that has eluded the adults in the room for more than a decade and a half. This is the truth about what we have attempted to do in Afghanistan and Iraq. Put aside your feelings about the desirability of overthrowing Saddam Hussein. Ask yourself instead why, if we consider ourselves totally responsible for the defenses of these countries, we bothered setting up quasi-democratic governments for them. Why not instead create a governor-general of Afghanistan who rules by presidential appointment? Why not send, in addition to invasion-level military personnel, tens of thousands of American civilians to teach, to build infrastructure, to practice medicine? Our recent Middle Eastern adventures have had all the hang-ups of colonialism and very few of the benefits — for us or anyone else. We must either rule or leave — there is no feasible middle course.

In Syria too Mattis and John Bolton would like to us to stay on indefinitely — not to dump water on the ashes of the Islamic State but to counteract Iran. But this is nonsense. Syria will remain within the Iranian (and Russian) sphere of influence for as long as Bashar al-Assad remains in power. If the adults in the room believe that Assad ought to be deposed, they should say so — and see what the American people think of the idea of another go round the regime change carousel. The principle that if you cannot get exactly what you want you should settle for the next best thing rarely applies in warfare.

Despite his reputation as a tough-talking, no-nonsense military man, Mattis gave the impression throughout his tenure of being the sort of person who did not wish to be associated with anything that might embarrass him at a Georgetown dinner party. He should serve as a reminder of why we insist upon civilian control of the military. No one so recently removed from active service should ever be trusted to serve a president rather than the spendthrifts at the Pentagon.

None of this should be taken to suggest that Mattis is not an honorable public servant. He is certainly a man of decency and courage and a great patriot. But that does not make him wise or astute. Any step, however flat-footed or incremental, away from the consensus he embodies in the direction of reality is worth taking.