The departure of Steve Bannon from the White House is politics as theatre, although the audience cannot tell yet whether it is tragedy or farce. This scene has been introduced by unseen voices, known as “sources close to Mr Bannon”, warning from the wings. “Winter is here.” “There will be consequences.” “Steve is now unchained.” “Get ready for Bannon the barbarian.” “He’s going nuclear.”

Then Donald Trump’s former chief strategist went public in an interview with a Bloomberg reporter to suggest that the coming wintry apocalypse would be directed at President Trump’s enemies: “I’m leaving the White House and going to war for Trump against his opponents – on Capitol Hill, in the media, and in corporate America.”

But another on-the-record interview, with The Weekly Standard, gave a different impression: “The Trump presidency that we fought for, and won, is over. We still have a huge movement, and we will make something of this Trump presidency. But that presidency is over.” This suggests that Mr Bannon is preparing for the mother of all betrayal myths: that his “war” will be waged on the fifth columnists and traitors who have hijacked the cause that the Trump presidency was supposed to bring to fruition.

It is well known that Mr Bannon had his doubts, in the early days of Mr Trump’s run for the White House, about whether the candidate was the right vehicle for the ideology of the new conservatism: Christian, isolationist and anti-establishment. Now it would seem that he is preparing to blame the wrong turning taken by the Trump administration – whatever that may be – on the President’s remaining advisers.

Strategist Steve Bannon leaves Trump's turbulent White House

In time, it must be suspected, Mr Bannon will move on to blaming President Trump himself for failing to live up to the ideological purity of “the movement”, and the Unchained Barbarian will move on to try to find another champion.

So far, so Game of Thrones. But what does it mean for the Trump administration which, hard though it may sometimes be to remember, is the semi-functioning government of the richest and most powerful country in the world?

First, the good news. Mr Bannon’s departure weakens the isolationist strain of thinking in the White House. The President’s former chief strategist was the ideologue of the zero-sum view of the world: that if China were advancing economically, America must be retreating. His removal from the premises does not mean that President Trump will now appreciate that trade is mutually beneficial, but it does allow for some compromise with reality.

The bad news is that the departure of yet another senior staffer in the first seven months of Mr Trump’s presidency gives every impression of an administration in turmoil. It might have been possible to present the departures of Sean Spicer, press secretary, Anthony Scaramucci, press secretary, Reince Priebus, chief of staff, and Mr Bannon as evidence that John F Kelly, the new chief of staff, was belatedly establishing order on chaos. But in the wake of the President himself disgracing himself, with off-script comments appearing to suggest that some neo-Nazis were “good people” and equating the bad ones with anti-Nazi protesters, it is hard to believe that he has discovered the virtues of discipline and restraint.