When the President of the US decides to wilfully incriminate himself in a tweet, we’re better off without him as an ally

Trump is a danger to a British national interest better served by reversing the referendum result, remaining in the EU, and hugging civilised allies close until a semblance of sanity returns to DC

Trump's relationship to the Constitution is becoming murkier by the day (Reuters)

Donald Trump’s relationship with the document he swore to protect in January has become even more special.

He was always a quixotic voice on the US Constitution, adoring the Second Amendment (right to bear arms) as fiercely as he hates the First (right to free speech) for preventing him from suing newspapers for fair comment.

Yet however inconsistent his previous constitutional musings, they took a turn towards the deranged this weekend.

Traditionally, US citizens facing potential criminal charges have pled the Fifth (right not to self-incriminate) with such robotic frequency that it has become a movie cliche. Watch Miss Sloane, a scintillating thriller about the ineffably nauseating world of Washington lobbyists, and you’ll hear Jessica Chastain’s title character repeatedly stonewall a Congressional enquiry with the mantra: “I must respectfully decline to answer your question, based on my rights under the Fifth Amendment to the United States Constitution.”

Technically, nothing the tangerine huckster could do now, from shutting down South Dakota by executive order to nuking Andorra, has the power to shock. But throwing away a precious constitutional right, and actively choosing to incriminate himself when under no pressure to say anything, was a touch startling.

The relevant tweet came in response to Robert Mueller, the special counsel investigating collusion between Russia and the Trump campaign, flipping its onetime director. Mike Flynn has pled guilty to lying to the FBI over his dealings with Russian ambassador Sergey Kislyak before Trump took office.

It seems that Flynn was deputed by someone close to Trump to discuss sanctions with Kislyak in breach of the Logan Act forbidding private citizens dealing with foreign governments. If that and/or Flynn’s other extracurricular activities (trying to prevent a UN resolution condemning Israel for its settlements) deliberately undermined White House policy, it might not be a billion miles from treason.

Since Flynn has been charged with a trivial offence carrying a six month sentence, it is assumed he has agreed to serenade Mueller with sweet canary song. More arrests and charges are thought inevitable as the Kremlin walls close in on Donald Trump – though if he is sticking to the standard McDonald’s meal outlined in a new book (two Big Macs, two Filet-O-Fish, chocolate malt milk shake) it might be more accurate that Trump’s belly is closing in on the Kremlin walls. This may prove a two horse race between impeachment and infarction.

Whatever the state of his coronary arteries, the heartbreaking tweet he filed on Saturday went: "I had to fire General Flynn because he lied to the Vice President and the FBI … It is a shame because his actions during the transition were lawful. There was nothing to hide!”

Until then, he claimed he fired Flynn purely for lying to Mike Pence. Trump’s admission to knowing his short lived National Security Advisor had lied to the Feds before he urged previous special counsel James Comey to “go easy on Flynn” looks remarkably like a voluntary confession to the impeachable offence of obstructing justice.

That doesn’t guarantee impeachment, but it does give Trump grave cause for concern. In today’s dawn chorus tweet, he showed he understands why. “I never asked Comey to stop investigating Flynn. Just more Fake News covering another Comey lie!”

At this point, one could closely examine the detail of Comey’s testimony to a congressional hearing, barely challenged until now, about how Trump cleared the room of witnesses after dinner one night, isolated him, and urged him to not “to go after” Flynn.

But when it’s one person’s word against another, and one of the persons is Donald Trump, why waste the space? No reasonable person doubts that he first leaned on Comey, and then sacked him for disobeying an order framed, mafioso-style, as a request. If he did that knowing Flynn had broken the law, as he admits, the odds against him breaking new ground by granting a presidential pardon to himself.

So ends another tempestuous week in the eye of the Trumpnado. Retweeting Britain First’s Islamophoic propaganda films, misaddressing his reply to the Prime Minister’s rebuke to a Bognor housewife, dissing the Fifth in favour of wilful self-incrimination, and perjuring himself once again in the court of public opinion by accusing an honest man of lying. Behold the leader of the free world to whose good graces the non-Bognor Theresa May has seen fit to entrust our post-Brexit hopes of economic salvation.

There never was a prospect of a quick and generous trade deal with the US. Trade deals are never quick, and the United States is never generous in its commercial dealings with foreign powers on imaginary grounds of sentimental attachment. The one special thing about this relationship since 1945 is that they always take and we always give.

But since the flaw that defines Trump more clearly than infantile narcissism, proudful ignorance, default mendacity or hideous gluttony happens to be grudge-bearing vindictiveness, there is now every prospect of either no deal or a terrible deal being struck if this supersize-lies-with-everything McDonald’s presidency endures.

Not lovin’ it, a patriotic British Prime Minister would instruct MI6 to give Mueller whatever help it can in unravelling the special relationships with Russian businessmen that long predate his political career.

After this diplomatic Twitter spat, Donald Trump’s survival is a threat not only to common decency and global security. It is a danger to a British national interest more patently served than ever by reversing the referendum result, remaining in the EU, and hugging civilised allies close until a semblance of sanity returns to DC.