Let's ask a simple question: what, exactly, is the U.S. secretary of State supposed to do?

The State Department's website provides a helpful answer: "The Secretary of State, appointed by the President with the advice and consent of the Senate, is the President's chief foreign affairs adviser. The Secretary carries out the President's foreign policies through the State Department."

Now let's ask the deeper question: If this is what the State Department's own website thinks America's chief diplomat is supposed to, then is Rex Tillerson actually the secretary of State? I have my doubts.

This is not a minor issue. Right now the Trump administration is attempting to defuse a mini-crisis in the Persian Gulf, in which Saudi Arabia and the rest of the Gulf Cooperation Council is pressuring the country that hosts the largest U.S. military base in the region. There is also the much larger crisis of North Korea test-firing an ICBM and the United States left with no good policy option. And finally, there are the Trump-created crises of the United States retreat from global leadership and the fast erosion of America's standing in the world.

This is a moment when the United States needs the secretary of State to do his job. As the New York Times noted 10 days ago, however, it is far from clear whether Tillerson is acting as the president's chief foreign affairs adviser. Their public disagreements over Qatar are just the tip of the iceberg:

"Some in the White House say that the discord in the Qatar dispute is part of a broader struggle over who is in charge of Middle East policy — Mr. Tillerson or Jared Kushner, the president's son-in-law and a senior adviser — and that the secretaryof state has a tin ear about the political realities of the Trump administration. Others say it is merely symptomatic of a dysfunctional State Department that, under Mr. Tillerson's uncertain leadership, does not yet have in place the senior political appointees who make the wheels of diplomacy turn.

"But criticism from Mr. Trump's aides is not Mr. Tillerson's only problem. In recent days, each of his top priorities has hit a wall. His effort to enlist China to force North Korea to give up its nuclear and ballistic missile programs has gone nowhere, as the president himself acknowledged last week. The Russians, angry about a congressional move to impose new sanctions, disinvited one of his top diplomats — leaving that crucial relationship at its lowest point since the Cold War.

"And in Congress, where Mr. Tillerson once found members willing to give deference to his efforts to reorganize and shrink the State Department, there is now anger and defiance about the extent of those plans."

More recent analyses have been just as scathing. How has Tillerson wound up in such an untenable position?

Recall what international relations scholar Robert Jervis wrote in March when he described Tillerson as the "weakest secretary of State ever":

"The secretary of state draws his or her power less from the U.S. Constitution or the laws than from five sources: backing from the president, advice and support from his or her department's career officials, admiration from and alliances with other leaders in the government, praise from the press and public, and positive evaluations of his or her competence and power by foreign diplomats. These individuals and groups do not act independently but rather depend on each other and interact to build up or tear down the secretary's power. Perceptions and reality blend as to be seen as powerful or weak, and that can readily become self-fulfilling in the Washington echo chamber."

Let's consider how Tillerson's relationship with these five sources has evolved in recent months:

1) Foreign diplomats. Tillerson has flailed badly. The same Times story notes, "Three foreign ambassadors — one from Asia and two from Europe — said they had taken to contacting the National Security Council because the State Department does not return their calls or does not offer substantive answers when it does."

Similarly, a Southeast Asian ambassador told the Los Angeles Times' Tracy Wilkinson, "There's just no one to talk to at the State Department." Wilkinson's story suggested that key allies preferred dealing with Jared Kushner to Tillerson. Even in the Middle East, presumably an area where Tillerson's network should be pretty good from his ExxonMobil days, Steve Coll, the author of "Private Empire: ExxonMobil and American Power," told Bloomberg, "This is not yesterday's Saudi Arabia, and Tillerson's relationships with the old guard are inevitably somewhat out of date." It would appear that Tillerson has few allies in the foreign diplomatic corps.

2) The press. If Tillerson has strained ties with his foreign counterparts, his relationship with the press is even worse. He got off to a bad start in this area and communications adviser R.C. Hammond has not helped Tillerson's case with his treatment of reporters. The primary themes of Tillerson press coverage in recent weeks has been that he's too walled off by his inner circle or that he's flip-flopped on a Middle East policy or that he's ignoring State Department experts. Neither Tillerson not his team are doing a good job of spinning.

3) Other foreign policy principals. The one positive angle in the press coverage on Tillerson is that he seems to have forged a good relationship with Secretary of Defense James Mattis. That's not nothing.

On the other hand, Tillerson seems to have lost a lot of credibility in Congress, which is definitely a problem. He also seems to have run afoul of the White House staff, with reports of him losing his temper at two different White House aides. The very fact that those stories ran suggests that the White House staff feels no concern about roasting him in public. I can certainly sympathize with Tillerson's side in these disputes, but the fact that he has created enemies inside the White House undercuts his standing.

4) The State Department. It would be hard to overstate just how badly Tillerson has alienated the professionals in the building. Tillerson's endorsement of severe budget cuts has likely been the biggest problem for him, but hardly the only one. Simply put, the so-called secretary of State has crushed the morale of America's diplomats. Max Bergmann, who served in the department from 2011 until earlier this year, visited Foggy Bottom recently and wrote the following for Politico:

"As I made the rounds and spoke with usually buttoned-up career officials, some who I knew well, some who I didn't, from a cross section of offices covering various regions and functions, no one held back. To a person, I heard that the State Department was in 'chaos,' 'a disaster,' 'terrible,' the leadership 'totally incompetent.' This reflected what I had been hearing the past few months from friends still inside the department, but hearing it in rapid fire made my stomach churn. As I walked through the halls once stalked by diplomatic giants like Dean Acheson and James Baker, the deconstruction was literally visible. Furniture from now-closed offices crowded the hallways. Dropping in on one of my old offices, I expected to see a former colleague-a career senior foreign service officer-but was stunned to find out she had been abruptly forced into retirement and had departed the previous week. This office, once bustling, had just one person present, keeping on the lights."

Meanwhile, Tillerson relied on the consultant firm Insigniam for guidance and feedback into reforming the State Department's bureaucracy. This firm surveyed 35,000 State Department and USAID employees. The Wall Street Journal's Felicia Schwartz has seen the report, and it's not all that pretty for Tillerson:

"State Department employees indicated to Insigniam that they are concerned both about the Trump administration and about Mr. Tillerson's leadership.

" 'People question if these two groups understand the role the Department of State plays in forwarding the interests of the United States in the world,' the report says.

"One respondent quoted in the report said: 'I am concerned that the dramatic reduction in budget, paired with extended staffing gaps at the most senior level, will result in the loss of not only an exceptionally talented group of people from our ranks, but will hamper our impact to fulfill our mission for decades to come.'

It is safe to say that Tillerson has alienated most of Foggy Bottom. Which leaves us with. . .

5) The president. To be fair, other secretaries of State have kept their distance from the building, from the press, and from foreign governments but went on to be successful. The key to that strategy is fostering a close relationship with the president. And one can see that this has been where Tillerson has put all of his chips. He has adhered to Donald Trump's draconian budget cuts to stay in his good graces. According to Politico, he has met face-to-face with Trump 37 times this year. Clearly, Tillerson thinks that more face-time with Trump will translate into more influence over policy — and, in turn, more perceived influence by external observers.

There is a sound logic to this gambit. The only problem is that the president is Trump, a man so mercurial and inconstant that no amount of face time will keep him on a consistent path. He has therefore contradicted his secretary of State on numerous occasions, such as climate change and Qatar. The White House appears to be thwarting all of Tillerson's staffing choices at Foggy Bottom. The American Conservative's Mark Perry sums up the current state of play after Trump overruled Tillerson on Qatar:

"A close associate of the secretary of state says that Tillerson was not only 'blind-sided by the Trump statement' but 'absolutely enraged that the White House and State Department weren't on the same page.' Tillerson's aides, I was told, were convinced that the true author of Trump's statement was U.A.E. ambassador Yousef Al Otaiba, a close friend of Trump son-in-law Jared Kushner. 'Rex put two-and-two together,' his close associate says, 'and concluded that this absolutely vacuous kid was running a second foreign policy out of the White House family quarters. Otaiba weighed in with Jared and Jared weighed in with Trump. What a mess.' The Trump statement was nearly the last straw for Tillerson, this close associate explains: 'Rex is just exhausted. He can't get any of his appointments approved and is running around the world cleaning up after a president whose primary foreign policy adviser is a 36-year-old amateur.' "

The contrast between Tillerson and Mattis here is revealing. The secretary of Defense has butted heads with the White House on personnel and policy as well. Nonetheless, Mattis has also been better at playing nice with the press, boosting morale inside the Pentagon, and forging links with other countries. Unsurprisingly, he is viewed as more successful in getting his way on policy matters.

Mattis has been a good secretary of Defense in a difficult situation. Furthermore, by the State Department's own definition, Mattis appears to be functioning as the secretary of State as well.

It's nice that Rex Tillerson found a job to transition from CEO of ExxonMobil to retirement. But maybe he should just hand over that job to someone who actually wants it and knows what to do with it.

- Drezner is a professor of international politics at the Fletcher School of Law and Diplomacy at Tufts University.