Image copyright KEVIN DIETSCH / POOL Image caption Mr Tillerson and Mr Trump share a complex relationship

US Secretary of State Rex Tillerson dismissed as "laughable" on Friday reports that his job security is uncertain.

But rumours that the White House is considering a plan to replace him because of tensions with President Donald Trump have swirled in Washington DC for months.

In a tweet, Mr Trump categorically denied the rumours as fake news, saying Mr Tillerson was "not leaving". The State Department has said it is business as usual.

Meanwhile, the drama is further disrupting the already dysfunctional way foreign policy is run in this administration.

So here are my takeaways on where things stand.

Takeaway 1: A complex relationship

It clearly has not been a happy one since the summer, starting with Mr Trump's politicised speech to the Boy Scouts of America, an organisation that Mr Tillerson used to head.

The secretary of state also distanced himself from the president's equivocal response to the white supremacist rally in Charlottesville.

Then there was that extraordinary moment in October when Mr Trump suggested an IQ-test challenge after a report that Mr Tillerson had called him a moron (which the latter denounced but did not deny, although his spokeswoman eventually did).

The two have also aired striking policy differences in public: several times Mr Trump has openly undermined Mr Tillerson's positions with his tweets.

Yet the president has quietly accepted his secretary of state's diplomatic strategy on some issues, such as dealing with North Korea tensions, co-operating with Russia for a political settlement of the Syrian civil war, and agreeing to punt the Iran nuclear deal to Congress rather than abandoning it outright.

He also gave Mr Tillerson a shout out during his recent trip to Asia, where the two men shared plenty of quality time. But they are chalk and cheese in temperament and the way they work, which matters to a president who operates on instinct and interaction.

And Mr Tillerson has not really learned to play the game of Washington politics - nor does he seem interested in doing so. Which means that if this is a game to try and force him out, it is not clear if he will follow the rules.

CIA director Mike Pompeo is being lined up to replace Mr Tillerson, according to the Beltway rumour mill.

Mr Pompeo plays it well and has cultivated a relationship with Mr Trump, making a point of delivering his intelligence briefings in person. His positions are also much more in line with Mr Trump's tough approach to national security.

Takeaway 2: A deeply dysfunctional house

I am struck by the parallel universes inhabited by the secretary and his critics at the state department. According to Mr Tillerson, it is functioning well - figures show about the same number of Foreign Service Officers now as this time last year.

It is not being hollowed out, Mr Tillerson says: such reports offend him on behalf of the hardworking career diplomats who have stepped into acting roles during an excruciatingly slow process of appointing political nominees.

As for his controversial redesign of the department, he says changes to its organisation and technology are badly needed. No one disputes that the state department needs to be dragged into the 21st Century.

And at least one anecdotal report from someone who is engaged with the "employee-led" process sounded upbeat about the prospects for organisational reform. But we don't hear much from these employees leading the process, we do not hear much of anything at all.

More importantly to veteran diplomats, Mr Tillerson has not spelled out what strategy and priorities lie behind his drawing board: the department will be smaller and more efficient, but what will it be for?

And even if the numbers are stable, the expertise is draining away. Dozens of senior officials have been removed from their positions or taken early retirement. Hiring and promotion freezes mean they are not currently being replaced. Communication is a serious problem: between Mr Tillerson's staff and the rest of the building, and with the press.

Those of us who travel with the secretary find him personable, straightforward, and seriously engaged with the issues. But there is no importance placed on delivering his message to the wider public.

He travels in a smaller plane, which means a scaled back staff that does not give regular updates about his movements, and turns the trips into logistical nightmares.

Morale at the state department is rock bottom.

Takeaway 3: How can he do his job?

The political intrigue that may unseat Mr Tillerson is separate from the state of the state department, but together they have undercut the effectiveness of US diplomacy.

And all this has contributed to confusion about what America stands for. "The whole administration suffers from not having articulated a clear vision for what American foreign policy is beyond the bumper sticker slogan of America First," Harvard international affairs professor Stephen Walt told me. Nor have they articulated how they will achieve that with a reformed state department.

Mr Tillerson has begun to try and define policy in a more systematic way region by region. His recent speech on Europe was the least "America First" one I have heard from this administration - extolling historic ties and emphasising the importance of and commitment to the transatlantic alliance in the face of a resurgent Russia.

But when he travels to Europe next week, will he be taken seriously? How much weight will governments there give his words if he does not appear to have the president's confidence? And how much longer can he operate this way, even if he is not sacked?