Donald Trump is going through the motions of being President of the United States. He still lives resides at 1600 Pennsylvania Avenue, he is still the head of the executive branch, and he's still the commander-in-chief of the world's most powerful military force.

He can still give orders and be reasonably sure that they will be followed, like the order he gave to a small group of US soldiers 12 days ago, requiring them to abandon the Syrian Kurdish allies with whom they'd shed blood on the way to defeating Isis. Those soldiers, loyal American servicemen, will follow those orders, even though doing so made them — in the words of one soldier — “ashamed for the first time in my career.”

But ordering US servicemen to and fro seems to be the limit of Trump's power at the moment. Because the rest of the world has figured Donald Trump out.

Such was the degree of anger at Trump's sudden abandonment of America's Kurdish allies — seemingly for no other reason than to please Turkey's leader — that on Wednesday, all but 60 House Republicans joined Speaker Nancy Pelosi's caucus to approve a resolution condemning the move, 354-60. In the Senate, a bipartisan group of senators is readying legislation to impose crippling sanctions on the Turkish regime, with a veto-proof majority expected to join their House colleagues in expressing their disapproval of the Trump administration's enabling of Erdogan's ethnic cleansing.

But Trump seems to think he's doing great and that everything is fine.

After the House dealt his Turkey policy a humiliating rebuke, Pelosi and the rest of the House and Senate leadership gathered at the White House for a briefing on the disastrous situation Trump had created. The president was so eager to boast of the "tough" stance he'd taken that he distributed a letter he'd sent to Erdogan — a letter which was so bizarre and childish in its wording that when it inevitably leaked to the media, journalists had to double-check to make sure it wasn't fake.

Turkish president Erdogan responds to Trump's extraordinary letter

According to Pelosi, he "was not relating to the reality" that a supermajority of House members disagreed with him, to the point where she walked out of the meeting, joined by House Majority Leader Steny Hoyer and Senate Minority Leader Chuck Schumer.

Schumer explained how he'd reminded Trump of the dangerous conditions that could be created with the release of Isis fighters who'd been held by Kurdish forces, and noted that even retired Marine General James Mattis — Trump's former Secretary of Defense — had said that pulling out of Syria would enhance the terrorist group. According to a source who was in the meeting, Trump's response was to call Mattis "the world's most overrated general" and declare that he had personally "captured Isis in a month."

Another source, who spoke to CNN's Jamie Gangel, said that Trump's demeanor left even Republicans "completely shaken," "shell-shocked" and "sickened."

"He is not in control of himself, it is all yelling and screaming," the source said, adding that Trump was "100 per cent worse" and that even Republicans are now worried about his stability.

As if to prove the anonymous source's point, Trump has spent the past two days claiming that he has brought peace to the region, rather than hand an unearned victory to Erdogan, Vladimir Putin, and Bashar al-Assad.

"Without spilling a drop of American blood… we've all agreed on a pause or ceasefire in the border region of Syria," the president said while speaking at a rally on Thursday, failing to mention that militias backed by Turkey have continued to fire on Kurdish forces during the five-day “pause".

While congressional Republicans may be surprised to discover that Trump's present grip on reality seems tenuous at best, it's no surprise to Dr Bandy Lee, an assistant clinical professor at the Yale School of Medicine and the editor of The Dangerous Case of Donald Trump, which contains essays from 27 mental health professionals on the "clear and present danger" posed by The Donald’s mental health (or lack thereof).

"It's gotten to the point where you don't have to be a doctor to see there's something seriously wrong here," Lee told me, adding that the decline into instability many are now observing in Trump was actually made inevitable by his ascent to the presidency. "Such mental instability in a position of power would eventually get worse because of rising expectations after the taste of power with the constraints of reality catching up with them."

Lee explained that although she has not examined Trump personally, she and a group of mental health experts concluded that based on the reports of his conduct contained in Special Counsel Robert Mueller's report, Trump "doesn't have the mental capacity to carry out his duties."

Lee and the other experts she's worked with joined more than 200 mental health professionals in signing a letter to members of Congress, in which they warned that "the unfolding of an impeachment inquiry raises the specter of President Trump feeling threatened in ways he never has before."

"We also should not ignore the president’s ability to initiate a conflict with other countries in order to distract from his political troubles, perhaps with the hope of rallying the country around him, as often happens at the beginning of armed conflict," they wrote in the letter, which is dated October 3, three days before Trump ordered US special forces to leave their Kurdish allies behind.

"What happened over the last week is the result of his irrational decision-making under increasing pressures," she said to me. ”He will make decisions without heeding advice, he will not be able to take in facts, he will be impulsive in his decision-making, he will not be able to make sound reality-based decisions… That's all we've seen over the last week and a half."

Although Trump's defenders argue that the analysis of Lee and her colleagues is invalid because none of them have examined or even met President Trump, Skybridge Capital founder Anthony Scaramucci has met him, and he sees things pretty much the same way.

Trump impeachment: Who's who in the Ukraine scandal Show all 26 1 /26 Trump impeachment: Who's who in the Ukraine scandal Trump impeachment: Who's who in the Ukraine scandal Donald Trump Accused of abusing his office by pressing the Ukrainian president in a July phone call to help dig up dirt on Joe Biden, who may be his Democratic rival in the 2020 election. He also believes that Hillary Clinton’s deleted emails - a key factor in the 2016 election - may be in Ukraine, although it is not clear why. EPA Trump impeachment: Who's who in the Ukraine scandal The Whistleblower Believed to be a CIA agent who spent time at the White House, his complaint was largely based on second and third-hand accounts from worried White House staff. Although this is not unusual for such complaints, Trump and his supporters have seized on it to imply that his information is not reliable. Expected to give evidence to Congress voluntarily and in secret. Getty Trump impeachment: Who's who in the Ukraine scandal The Second Whistleblower The lawyer for the first intelligence whistleblower is also representing a second whistleblower regarding the President's actions. Attorney Mark Zaid said that he and other lawyers on his team are now representing the second person, who is said to work in the intelligence community and has first-hand knowledge that supports claims made by the first whistleblower and has spoken to the intelligence community's inspector general. The second whistleblower has not yet filed their own complaint, but does not need to to be considered an official whistleblower. Getty Trump impeachment: Who's who in the Ukraine scandal Rudy Giuliani Former mayor of New York, whose management of the aftermath of the September 11 attacks in 2001 won him worldwide praise. As Trump’s personal attorney he has been trying to find compromising material about the president’s enemies in Ukraine in what some have termed a “shadow” foreign policy. In a series of eccentric TV appearances he has claimed that the US state department asked him to get involved. Giuliani insists that he is fighting corruption on Trump’s behalf and has called himself a “hero”. AP Trump impeachment: Who's who in the Ukraine scandal Volodymyr Zelensky The newly elected Ukrainian president - a former comic actor best known for playing a man who becomes president by accident - is seen frantically agreeing with Trump in the partial transcript of their July phone call released by the White House. With a Russian-backed insurgency in the east of his country, and the Crimea region seized by Vladimir Putin in 2014, Zelensky will have been eager to please his American counterpart, who had suspended vital military aid before their phone conversation. He says there was no pressure on him from Trump to do him the “favour” he was asked for. Zelensky appeared at an awkward press conference with Trump in New York during the United Nations general assembly, looking particularly uncomfortable when the American suggested he take part in talks with Putin. AFP/Getty Trump impeachment: Who's who in the Ukraine scandal Mike Pence The vice-president was not on the controversial July call to the Ukrainian president but did get a read-out later. However, Trump announced that Pence had had “one or two” phone conversations of a similar nature, dragging him into the crisis. Pence himself denies any knowledge of any wrongdoing and has insisted that there is no issue with Trump’s actions. It has been speculated that Trump involved Pence as an insurance policy - if both are removed from power the presidency would go to Democratic House Speaker Nancy Pelosi, something no Republican would allow. AP Trump impeachment: Who's who in the Ukraine scandal Rick Perry Trump reportedly told a meeting of Republicans that he made the controversial call to the Ukrainian president at the urging of his own energy secretary, Rick Perry, and that he didn’t even want to. The president apparently said that Perry wanted him to talk about liquefied natural gas - although there is no mention of it in the partial transcript of the phone call released by the White House. It is thought that Perry will step down from his role at the end of the year. Getty Trump impeachment: Who's who in the Ukraine scandal Joe Biden The former vice-president is one of the frontrunners to win the Democratic nomination, which would make him Trump’s opponent in the 2020 election. Trump says that Biden pressured Ukraine to sack a prosecutor who was investigating an energy company that Biden’s son Hunter was on the board of, refusing to release US aid until this was done. However, pressure to fire the prosecutor came on a wide front from western countries. It is also believed that the investigation into the company, Burisma, had long been dormant. Reuters Trump impeachment: Who's who in the Ukraine scandal Hunter Biden Joe Biden’s son has been accused of corruption by the president because of his business dealings in Ukraine and China. However, Trump has yet to produce any evidence of corruption and Biden’s lawyer insists he has done nothing wrong. AP Trump impeachment: Who's who in the Ukraine scandal William Barr The attorney-general, who proved his loyalty to Trump with his handling of the Mueller report, was mentioned in the Ukraine call as someone president Volodymyr Zelensky should talk to about following up Trump’s preoccupations with the Biden’s and the Clinton emails. Nancy Pelosi has accused Barr of being part of a “cover-up of a cover-up”. AP Trump impeachment: Who's who in the Ukraine scandal Mike Pompeo The secretary of state initially implied he knew little about the Ukraine phone call - but it later emerged that he was listening in at the time. He has since suggested that asking foreign leaders for favours is simply how international politics works. Gordon Sondland testified that Pompeo was "in the loop" and knew what was happening in Ukraine. Pompeo has been criticised for not standing up for diplomats under his command when they were publicly criticised by the president. AFP via Getty Trump impeachment: Who's who in the Ukraine scandal Nancy Pelosi The Democratic Speaker of the House had long resisted calls from within her own party to back a formal impeachment process against the president, apparently fearing a backlash from voters. On September 24, amid reports of the Ukraine call and the day before the White House released a partial transcript of it, she relented and announced an inquiry, saying: “The president must be held accountable. No one is above the law.” Getty Trump impeachment: Who's who in the Ukraine scandal Adam Schiff Democratic chairman of the House intelligence committee, one of the three committees leading the inquiry. He was criticized by Republicans for giving what he called a “parody” of the Ukraine phone call during a hearing, with Trump and others saying he had been pretending that his damning characterisation was a verbatim reading of the phone call. He has also been criticised for claiming that his committee had had no contact with the whistleblower, only for it to emerge that the intelligence agent had contacted a staff member on the committee for guidance before filing the complaint. The Washington Post awarded Schiff a “four Pinocchios” rating, its worst rating for a dishonest statement. Reuters Trump impeachment: Who's who in the Ukraine scandal Lev Parnas and Igor Fruman Florida-based businessmen and Republican donors Lev Parnas (pictured with Rudy Giuliani) and Igor Fruman were arrested on suspicion of campaign finance violations at Dulles International Airport near Washington DC on 9 October. Separately the Associated Press has reported that they were both involved in efforts to replace the management of Ukraine's gas company, Naftogaz, with new bosses who would steer lucrative contracts towards companies controlled by Trump allies. There is no suggestion of any criminal activity in these efforts. Reuters Trump impeachment: Who's who in the Ukraine scandal William Taylor The most senior US diplomat in Ukraine and the former ambassador there. As one of the first two witnesses in the public impeachment hearings, Taylor dropped an early bombshell by revealing that one of his staff – later identified as diplomat David Holmes – overheard a phone conversation in which Donald Trump could be heard asking about “investigations” the very day after asking the Ukrainian president to investigate his political enemies. Taylor expressed his concern at reported plans to withhold US aid in return for political smears against Trump’s opponents, saying: “It's one thing to try to leverage a meeting in the White House. It's another thing, I thought, to leverage security assistance -- security assistance to a country at war, dependent on both the security assistance and the demonstration of support." Getty Images Trump impeachment: Who's who in the Ukraine scandal George Kent A state department official who appeared alongside William Taylor wearing a bow tie that was later mocked by the president. He accused Rudy Giuliani, Mr Trump’s personal lawyer, of leading a “campaign of lies” against Marie Yovanovitch, who was forced out of her job as US ambassador to Ukraine for apparently standing in the way of efforts to smear Democrats. Getty Images Trump impeachment: Who's who in the Ukraine scandal Marie Yovanovitch One of the most striking witnesses to give evidence at the public hearings, the former US ambassador to Ukraine received a rare round of applause as she left the committee room after testifying. Canadian-born Yovanovitch was attacked on Twitter by Donald Trump while she was actually testifying, giving Democrats the chance to ask her to respond. She said she found the attack “very intimidating”. Trump had already threatened her in his 25 July phone call to the Ukrainian president saying: “She’s going to go through some things.” Yovanovitch said she was “shocked, appalled and devastated” by the threat and by the way she was forced out of her job without explanation. REUTERS Trump impeachment: Who's who in the Ukraine scandal Alexander Vindman A decorated Iraq War veteran and an immigrant from the former Soviet Union, Lt Col Vindman began his evidence with an eye-catching statement about the freedoms America afforded him and his family to speak truth to power without fear of punishment. One of the few witnesses to have actually listened to Trump’s 25 July call with the Ukrainian president, he said he found the conversation so inappropriate that he was compelled to report it to the White House counsel. Trump later mocked him for wearing his military uniform and insisting on being addressed by his rank. Getty Images Trump impeachment: Who's who in the Ukraine scandal Jennifer Williams A state department official acting as a Russia expert for vice-president Mike Pence, Ms Williams also listened in on the 25 July phone call. She testified that she found it “unusual” because it focused on domestic politics in terms of Trump asking a foreign leader to investigate his political opponents. Getty Images Trump impeachment: Who's who in the Ukraine scandal Kurt Volker The former special envoy to Ukraine was one of the few people giving evidence who was on the Republican witness list although what he had to say may not have been too helpful to their cause. He dismissed the idea that Joe Biden had done anything corrupt, a theory spun without evidence by the president and his allies. He said that he thought the US should be supporting Ukraine’s reforms and that the scheme to find dirt on Democrats did not serve the national interest. Getty Images Trump impeachment: Who's who in the Ukraine scandal Tim Morrison An expert on the National Security Council and another witness on the Republican list. He testified that he did not think the president had done anything illegal but admitted that he feared it would create a political storm if it became public. He said he believed the moving the record of the controversial 25 July phone call to a top security server had been an innocent mistake. Getty Images Trump impeachment: Who's who in the Ukraine scandal Gordon Sondland In explosive testimony, one of the men at the centre of the scandal got right to the point in his opening testimony: “Was there a quid pro quo? Yes,” said the US ambassador to the EU who was a prime mover in efforts in Ukraine to link the release of military aid with investigations into the president’s political opponents. He said that everyone knew what was going on, implicating vice-president Mike Pence and secretary of state Mike Pompeo. The effect of his evidence is perhaps best illustrated by the reaction of Mr Trump who went from calling Sondland a “great American” a few weeks earlier to claiming that he barely knew him. AP Trump impeachment: Who's who in the Ukraine scandal Laura Cooper A Pentagon official, Cooper said Ukrainian officials knew that US aid was being withheld before it became public knowledge in August – undermining a Republican argument that there can’t have been a quid pro quo between aid and investigations if the Ukrainians didn’t know that aid was being withheld. Getty Images Trump impeachment: Who's who in the Ukraine scandal David Hale The third most senior official at the state department. Hale testified about the treatment of Marie Yovanovitch and the smear campaign that culminated in her being recalled from her posting as US ambassador to Ukraine. He said: “I believe that she should have been able to stay at post and continue to do the outstanding work.” EPA Trump impeachment: Who's who in the Ukraine scandal Fiona Hill Arguably the most confident and self-possessed of the witnesses in the public hearings phase, the Durham-born former NSC Russia expert began by warning Republicans not to keep repeating Kremlin-backed conspiracy theories. In a distinctive northeastern English accent, Dr Hill went on to describe how she had argued with Gordon Sondland about his interference in Ukraine matters until she realised that while she and her colleagues were focused on national security, Sondland was “being involved in a domestic political errand”. She said: “I did say to him, ‘Ambassador Sondland, Gordon, this is going to blow up’. And here we are.” AP Trump impeachment: Who's who in the Ukraine scandal David Holmes The Ukraine-based diplomat described being in a restaurant in Kiev with Gordon Sondland while the latter phoned Donald Trump. Holmes said he could hear the president on the other end of the line – because his voice was so “loud and distinctive” and because Sondland had to hold the phone away from his ear – asking about the “investigations” and whether the Ukrainian president would cooperate. REUTERS

"It is painful to watch the deconstruction of Donald Trump...and the full-blown meltdown that I've been talking about over the past few months,” said Scaramucci, who was a longtime friend of the president when he briefly served as White House Communications Director, but is now one of Trump's most prominent critics.

But Scaramucci doesn't think Trump has lost his grip on reality.

"He's buying into the whole Fox conspiracy narrative, but he's still aware enough to know that there's a serious issue going on," he said, but noted that some of Trump's recent actions — including his decision to abandon the Kurds in Syria — don't seem to have any explanation except potentially a financial one. "Someone needs to ask what was in it for him personally."

Still, Scaramucci said he finds it "disheartening" that more Republicans are not speaking out about what he says is an obvious fact: That Trump is "getting worse and worse" each week.

"There seems to be a compounding effect because he's deteriorating more aggressively," he said, adding that in his opinion, Trump's decline will eventually lead someone else to be the one to square off against the winner of the Democratic primary.