Former Secretary of Defense James Mattis announced his resignation Dec. 20. He left the job at the end of the year. That was seven weeks ago, and President Trump hasn’t nominated a permanent replacement.

How rare is that? There have only been two acting defense secretaries since the department began in 1947. In 1973, President Richard Nixon nominated James Schlesinger to replace Elliot Richardson, who was confirmed as attorney general a few weeks later. But Schlesinger wasn’t confirmed and sworn in for about six weeks, so an acting defense secretary was needed. Then, in 1989, an acting secretary was needed from Jan. 20 to March 21 as President George H.W. Bush’s first choice, John Tower, went through a prolonged and unsuccessful confirmation battle. That was followed by the confirmation of Bush’s second choice, Dick Cheney. In that case, Bush selected Cheney just one day after the Senate voted against Tower.

In other words, Trump is the first president to leave the Defense Department without a confirmed secretary just because the White House hasn’t nominated one.

And that’s not the only vacant position. There’s still an acting attorney general: The nominee, William Barr, hasn’t been confirmed, mainly because Trump didn’t nominate anyone from Nov. 7, when he fired Jeff Sessions, until Dec. 7. Acting attorneys general aren’t quite as rare as acting secretaries of defense, but a three-month gap is unusual. There’s also an acting secretary of the interior and an acting administrator of the Environment Protection Agency (a Cabinet-level post).

White House Chief of Staff Mick Mulvaney is also serving in an acting capacity, though the position isn’t Senate-confirmed, so it’s not clear exactly what “acting” means in this context. At any rate, Mulvaney kept his post at the Office of Management and Budget, which means there’s also an acting OMB director.

So Trump has had a full, confirmed Cabinet only from May 15 to July 31, 2017, and then again from Jan. 29 to March 28, 2018. That’s even though there has been a Republican majority in the Senate throughout Trump’s term, and only a simple majority is needed to confirm.

And those are only the highest-profile slots. There are still hundreds of unfilled offices across the executive branch, many without a presidential nominee.

Why? Trump himself says the vacancies are deliberate. “I like ‘acting’ because I can move so quickly,” he said last week.

It’s true that using an acting is a way to free a position from Senate influence. It’s also probably true that temporary Cabinet officers are overall more responsive to the president, since he can keep them in the position or get rid of them at far less cost than if he had to go through the nomination and confirmation process. But deliberately trying to govern that way is a kind of abuse of power that a Senate with more institutional self-interest would resist.

In addition, actings are almost certainly far less effective at managing their agencies and departments. One of the best bureaucratic weapons to oppose presidential preferences is simple inaction: Unless the president can increase pressure, it’s often a good bet that the permanent bureaucracy can just wait it out. But a confirmed secretary or agency director can push hard for the president’s program, increasing the costs to civil servants of resisting. Actings have limited formal and practical authority, and they are time-limited, so waiting them out is a far more tempting strategy.

The inaction on nominations is probably more inept presidenting than it is a complex plot. But it’s still terrible for the nation and an abuse of power.