With President Trump's announcement that he plans to nominate Kirstjen Nielsen as homeland security secretary, he still has one more Cabinet post to fill — health and human services secretary. A president having to find replacements for two Cabinet secretaries this early in an administration is unprecedented. But observers are more alarmed by the less visible vacancies at the sub-Cabinet level: hundreds of positions without a nominee, and a president who says he has no intention of filling many of the jobs.

"I'm generally not going to make a lot of the appointments that would normally be — because you don't need them," Trump said in an interview with Forbes Magazine last week. "I mean, you look at some of these agencies, how massive they are, and it's totally unnecessary. They have hundreds of thousands of people."

Asked about the president's comment, press secretary Sarah Sanders said that some jobs are in the process of being filled, with candidates going through an intensive vetting process, but that "the president came to Washington to drain the swamp and get rid of a lot of duplication, make government more efficient. And so if we can have one person do a job instead of six, then we certainly want to do that."

As North Korea intensifies its effort to become a nuclear-armed nation, threatening the U.S. and its allies, Trump still hasn't nominated key people to help develop the U.S. strategy and response. More than half of State Department positions requiring Senate confirmation still don't have a nominee, including the ambassador to South Korea and the assistant secretary for East Asian and Pacific affairs.

"This is not a question of not filling superfluous positions, of which there are many in government," said Danielle Pletka, senior vice president for foreign and defense policy studies at the right-leaning American Enterprise Institute. "This is a question of filling important positions."

Although other departments have a higher share of vacant positions, the sheer number of top-level positions open at the State Department and the high stakes involved in the work there make it especially notable.

On Friday, Trump is expected to announce a decision that could upend the Iran nuclear deal, and again, Pletka said, key appointed personnel are not in place to explain the president's decision to U.S. allies.

In the State Department alone, there is no nominee for ambassador to Egypt, Jordan, Saudi Arabia, Qatar or Turkey. And there is no assistant secretary for arms control or assistant secretary for international security and nonproliferation.

"Who's going to take that message to our Middle East allies? We don't have any ambassadors. Who's going to take that message to our Asian and European allies?" Pletka asked. "We. Don't. Have. Those. People."

Also not yet nominated in the State Department: the assistant secretary for Near East affairs and the assistant secretary for South and Central Asian affairs. The U.S. is engaged in ongoing military operations in both those regions.

At the Department of Homeland Security, where Trump just announced a pick for secretary, there are still no nominees for the critical positions of chief financial officer, assistant secretary for Immigration and Customs Enforcement and deputy administrator for the Federal Emergency Management Agency. This comes as Trump is pushing for aggressive immigration enforcement and as numerous states and Puerto Rico are trying to recover from natural disasters.

Of approximately 600 key appointed positions throughout the government that require Senate confirmation tracked by the Partnership for Public Service, "President Trump has only about a quarter that are actually in place, and we're nine months into his administration," said Max Stier, president and CEO of the nonpartisan group.

That "is way behind what any prior administration has been able to accomplish and is a big problem," Stier added.

In addition to Trump's slow pace for naming appointees, the Senate has also been slow to confirm his nominees.

And while Trump says he is creating efficiency by leaving positions without nominees, Stier and others say it's not that simple. Those open jobs are being filled on an interim basis by career civil servants and foreign service officers.

"But they are the proverbial substitute teacher; everyone knows you're not around for the long term," Stier said. "Whatever decisions you make aren't going to necessarily stick. You're not likely to take the long-term view or handle the most difficult issues."

The people put in acting positions are often senior career civil servants with 20 or 30 years working in those agencies, said Jon Alterman, senior vice president at the Center for Strategic and International Studies.

"They're just at the point where they do have a lot to lose and they become very risk-averse, and I think you want people to be cautious but you don't want them to be so risk-averse that they are afraid to act," said Alterman.

He says political appointees, confirmed by the Senate, have a bias toward action and bring fresh ideas. That is something you are less likely to get with a civil servant afraid of running afoul of the White House and ending a career.

What Pletka really doesn't understand is why a president who came to Washington promising to shake things up wouldn't want to install his own people to help him do just that.

"I'm actually just gobsmacked," said Pletka. "One of the most important things about running for president and about being elected president is that you do get to make your mark."

Political appointees are one of the significant ways past presidents have made their mark on federal agencies.

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