Image copyright Getty Images

It is as if the campaign is still going on.

Two weeks away from his inauguration, Donald Trump seems to prefer the role of "candidate" - flaying his opponents and aiming arrows at the federal government from the enemy camp.

It is almost as if he does not want to accept fully that he is the new chief executive who will be dealing with official Washington from the moment he drives back from the Capitol as the president on 20 January.

And his weapon of choice, forged for him like a legendary warrior's sword in the furnace of the new technology, is Twitter.

No president-elect has battled like this.

Most of them go to ground, secluded with the staff who will take over the West Wing, and make their plans. Dream their dreams, you might say.

They have followed the golden rule: do not give too much away, because it will make life more difficult when the inauguration is over and the business of power begins.

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The Trump Twitter account is not just a break with that pattern, but a challenge to the very idea.

His New Year tweet (one of them, I should say) wished love to everyone "including my many enemies and those who have fought me and lost so badly they just don't know what to do".

Image copyright AFP Image caption Mr Trump wished love to everyone via Twitter at the turn of the year

The implication, of course, is that he does know what he is going to do. The trouble with his Twitter account is that it makes you wonder.

More than 34,000 tweets to nearly 19 million followers (many "enemies" among them, no doubt) and a narrative that has become a kind of stream of consciousness. They read like the unfiltered, disconnected thoughts of someone for whom patience is an ugly word.

You always have to say something, even if you say the opposite the next day. On Twitter, who cares?

Yet, the messages are powerful. One contemptuous tweet about the new Republican majority in the House of Representatives winding down the Office of Congressional Ethics led them to beat a humiliating retreat and cancel the plan.

Mr Trump's choice as White House press secretary, Sean Spicer, said the other day: "Whatever he tweets, he is going to drive the news."

Image copyright Twitter

And, bizarre though it may seem, the South Korean government is poring over them. The JoongAng Daily reported that a Twitter-watching position had been set up in the foreign ministry in Seoul "because we don't yet have an insight into his foreign policies".

What insight will they get from tweets which have criticised the Central Intelligence Agency, praised Julian Assange - the Whistleblower of WikiLeaks and a bete noire to most Republicans - and praised President Putin, who gets more friendly treatment than all Democrats and some Republicans at home?

And remarkably the tweets take aim at the entire intelligence community in Washington. What precisely are the South Koreans meant to make of that?

Not too much, you may think, because who can tell how this mercurial candidate is going to be moulded into a president? We still do not know and what his Twitter account tells us - colourfully, astonishingly, sometimes hilariously - is that he is refusing to let us know.

Far from revealing what a Trump presidency is going to be like - as he says his tweets do - they have the effect of enveloping him in a thick fog.

Yes we know he will "make America great again", cut immigration, build his wall, cut taxes, be Israel's greatest ally and so on. But how he is going to build a White House team on foreign affairs and security, conduct relations with Capitol Hill, deal with allies in Nato and the rolling chaos in the Middle East, we have very little idea.

And when the first crisis arrives - as it will before long - will he be able to find the calm that he needs?

Image caption Where it all began: Trump's Twitter page in April 2009

No president-elect in modern times has said so much and revealed so little.

We know how Mr Trump feels about almost everything, but about priorities, his approach to the compromises of power, the way he will deal with the bureaucracy - in practice we know very little.

A week or two before election day in November, one of his close associates told me that, if he won, Mr Trump had agreed that in office he would relinquish control of that Twitter account, because it would be inappropriate in the White House.

The satirists' loss, certainly. But, if it happens, a step into reality, at last.

Some day he has to stop being the candidate and playing that game, even though he enjoys it so much.

So the first great test for the Trump White House team is surely getting his finger off that keyboard.