John J. Hamre, deputy secretary of defense from 1997 to 1999, is president and chief executive of the Center for Strategic and International Studies.

If President-elect Donald Trump wants to dramatically improve the functioning of government, here is one simple and straightforward thing he can do: refrain from flooding the Cabinet departments with politically appointed deputy assistant secretaries.

For decades, administrations have extended the ranks of political appointees to lower levels. Eager and well-meaning but largely inexperienced individuals have been made deputy assistant secretaries to head offices within the departments. Often this is the first real job these individuals have ever held. I know the Defense Department well and have watched the phenomenon unfold there, but it has occurred across the government. There generally are two consequences.

First, such appointees have little standing with the secretary, especially when they are handpicked by the White House and forced on the secretary to serve as an advance guard for the West Wing. And because they have little standing, they hunker down to protect their turf, amplifying whatever coordination problems exist within a department.

But the bigger problem is this: Historically, deputy assistant secretary positions were the capstone for highly skilled and experienced civil servants. These men and women had deep expertise and knew how government worked. And contrary to political appointees, civil servants are loyal to the Constitution, not to the previous administration. I have seen it for 30 years: Incoming political appointees deeply distrust senior civil servants, wrongly thinking, “They must not be any good if they worked for the bums that preceded me.”

I saw this in the transitions to the Clinton, George W. Bush and Obama administrations. Naive and inexperienced political appointees shunned the help of experienced civil servants out of the misguided assumption that civil servants were determined to subvert the new leadership. Incompetent appointees were preferred over professional, politically agnostic, experienced civil servants.

Trump can break this bad pattern. The president-elect doesn’t bring with him a standing army of think-tank types ready to take up the levers of power. He will have a sufficiently hard time finding competent undersecretaries and assistant secretaries. Make that the priority — and make a conscious decision to leave subordinate positions to senior civil servants. I have worked with them long enough to know that they are overwhelmingly dedicated to serving whatever administration is entrusted to run the government by the American people.