Fasten your seatbelts for the inauguration today of Donald Trump as the 45th President of the United States.

He is far and away the most unlikely, unorthodox and unpredictable leader ever to enter the Oval Office.

The ambush of the unexpected lurks behind his every pronouncement and move.

His capacity to surprise has wrong-footed the pundits of the mainstream U.S. media and blindsided the power elites of the world, from Beijing to Bonn to Brussels.

How, on Day One, can we predict how well or badly he will govern?

President-elect of The United States Donald J. Trump and First Lady-elect Melania Trump arrive Joint Base Andrews in Maryland

U.S. President-elect Donald Trump delivers remarks at a Make America Great Again welcome concert in Washington, U.S.

Some answers can be found by looking at his strategy for making deals with the superpowers, his impressive Cabinet appointees and his friendly overtures to post-Brexit Britain.

Trump’s domestic fan club lies in the silent majority of blue-collar voters who Hillary Clinton so unwisely mocked as ‘the deplorables’.

They rallied in droves to his call ‘to make America great again’.

They worship their hero for breaking the mould of conventional politics, which they feel has let them down.

Meanwhile, it is foreigners in distant capitals who are wringing their hands.

Angela Merkel will not enjoy being told she has made ‘a catastrophic mistake’ over German immigration policies.

The leaders of China, Mexico, Nato and the EU are no less discomfited by Trump’s strictures against them.

President-elect Donald Trump and his wife Melania Trump arrive at a pre-Inaugural 'Make America Great Again! Welcome Celebration' at the Lincoln Memorial in Washington

Britain, by contrast, is the only major country so far to have been elevated to a different league on the new President’s approval index.

The reasons for this go deeper than the Anglophile affability expressed in his interview in this week’s Times.

Trump’s desire to have a close relationship with Britain is based on a combination of empathy and enlightened self-interest.

It fits well with his administration’s emerging strategy to make deals on a country-by-country basis for the benefit of America’s trade and economic interests.

This is not multilateral protectionism.

It will be a bilateral transaction, with President Trump the great deal-maker, as master of the game.

Before examining the ground-breaking symbolism of Trump’s attitude to Britain, consider his highest international priority: deal-making with the superpowers.

I happen to know that Donald Trump had an intriguing and mutually admiring relationship with Richard Nixon (whose biography I wrote).

The first letter the 37th President sent to the new 45th President on December 21, 1987, has been framed and will be hung today in place of honour on the White House walls.

‘You were great . . . whenever you decide to run for office you will be a winner,’ wrote Nixon to the 41-year-old Trump. A prophetic utterance indeed!

But even more interesting is the contemporary prophesy among Trump insiders on how their boss plans to imitate Nixon’s greatest foreign policy triumph — but in reverse order: ‘Donald Trump will play Russia against China just as Richard Nixon played China against Russia. Just you watch.’

Donald Trump and his wife Melania

This discreet nugget of briefing to me from a senior member of the new administration’s foreign policy team is fascinating, and could well come true.

If Trump is going to bring back manufacturing prosperity to America’s rust belt, he needs to strike a deal with China to rein back their dumping of steel and other artificially cheap products on international markets.

Who could be his ally in pressuring Beijing to accept such restrictions in a new world trade order?

How about Vladimir Putin?

Trump has already signalled his willingness to negotiate with the Russian leader.

An early summit in Reykjavik is probable.

On the agenda would be reducing the nuclear arsenals of both sides; establishing a common fight against Isis terrorism; securing peace in Syria and persuading China to back off from the trade war hinted at by President Xi Jinping at the economic forum in Davos this week.

Could part or all of such a deal be pulled off?

Would attempting it mean, as some media commentators fear, that Trump’s America was going soft on Putin’s Russia?

This anxiety soon fades when the line-up of President Trump’s Cabinet appointees is considered.

Harken to the ancient words of wisdom from Niccolo Machiavelli: ‘The best way of judging the quality of a ruler is to study the brains of the men around him.’

President Trump passes the Machiavelli test with flying colours.

To my mind, this is the most heavyweight U.S. Cabinet since JFK’s in 1961, particularly in Defence, National Security and Foreign Affairs.

Henry Kissinger, the former Secretary of State, has also been quietly advising President-elect Trump for some months, focusing on Russia and China, where, even at the age of 93, he is a regular visitor.

The theory that this galaxy of geopolitical talent will allow President Trump to ‘go soft’ on Putin is absurd.

Returning to the domestic arena: no one should underestimate Trump’s commitment to fight for global reforms that will benefit America’s working middle class.

‘The Trump team will be a take-no-prisoners, back-alley, knife-fighting group of American-nationalist, America-first brass-knuckle street brawlers,’ says Texan pundit George Seay, my favourite and most perceptive Trump watcher.

Last October he predicted The Donald’s election victory in a series of brilliant — if sceptically received — speeches in Oxford, Cambridge, Edinburgh and London.

Now, Seay forecasts: ‘We are most likely in store for hardball politics and a ruthless pursuit of sharp turns to the Right, which may ignore free trade, international institutions and strain relations with U.S. allies overseas.’

As the new President’s No 1 approved U.S. ally, Britain is well placed to prosper through this turbulence.

Brexit is our bond.

Nigel Farage, praised by Donald Trump, holds aloft a British Union jack flag

Trump predicted it and almost thinks he invented it.

He praises the buccaneering spirit of leading Brexiteers Boris Johnson, David Davis, Liam Fox and especially Nigel Farage.

In the past few days, he has been privately singing the praises of Theresa May for the courage of her steely speech this week, throwing down the gauntlet to the EU monoliths.

These are good omens — particularly Trump’s promise to make a front-of-the-queue trade deal with us, saying: ‘We’re gonna work very hard to get it done quickly and done properly.’

While the bureaucrats flesh out the small print of a new UK-U.S.

trade treaty, hopefully making good use of the familiar ‘most favoured nation’ status granted in many an Act of Congress to selected U.S. trading partners, British businesses can start work immediately to capitalise on the goodwill of a Trump bounce.

There are solid foundations to build on.

America is Britain’s biggest single trading partner, accounting for 20 per cent of our commerce with the rest of the world.

Today, the U.S. buys $57 billion (£46 billion) worth of British exports a year.

More than three million Americans visit the UK every year, spending in excess of $10 billion (£8.1 billion) in our shops, tourist venues and hotels.

There are excellent prospects for a surge in these favourable figures thanks to the recent strengthening of the dollar and weakening of the pound, which will make Americans’ holiday money go further here.

The ‘Trump effect’ should make British export income and inward investment grow by at least 20 per cent thanks to the currency differentials alone.

Also, in Middle America, where Trump piled up the votes, the new President’s warm words about his mother’s homeland will increase the innate aura of pro-Britishness.

We should be rejoicing at the prospects of a speedy new UK-U.S. trade agreement, because where America leads, many other countries will follow.

This is in Washington’s interest, too.

President-elect of The United States Donald Trump and First Lady-elect Melania Trump arrive Joint Base Andrews in Maryland

Trump wants his future deal with Britain to be his prototype for new bilateral trade arrangements to replace old multilateral schemes like the North American Free Trade Agreement (between Canada, America and Mexico) and the Trans-Pacific Partnership Trade Agreement (TPP).

Trump needs Britain as his new best and pioneering friend, not only in trade reform but also as a supporter for his reform of Nato.

This has caused great fluttering in the dovecotes of those members who don’t pay their dues in terms of defence spending, or pull their weight, but it’s right.

When I was a Defence Minister, we fully committed; and paying Brits were often frustrated by what was privately called Nato-sclerosis.

But we did not dare to speak our minds for fear of upsetting our European allies.

Trump will blow away such cobwebs.

Also on the military front, there is scope for special Anglo-U.S. co-operation in areas such as submarine warfare and developing the latest weapons technology, in which we would lead the world.

British defence and aerospace companies like BAE, Rolls-Royce and GKN could do well in winning orders from a Trump Pentagon with whom we should be working even more closely.

Donald Trump will be sworn in as the 45th President of the United States of America today

Finally, we should keep in mind that this hyper-energetic, earth-shaking American life-force, who takes the oath of office today, can be moved just as much by his sentiments, his instincts and his intuitions as by the conventional statecraft recommendations made to him by Washington insiders.

Again, this is a big plus for Britain.

Trump loves his Scottish roots, reveres the memory of his Isle of Lewis-born mother, and proudly proclaims himself to be an Anglophile.

He feels a rapport for the merchant adventuring spirit of old Britain, which he thinks will be reborn in the brave new world of Brexit.

This gives us the chance to seize the moment and the opportunities as the first 100 days of the new presidency begin.

Trump says he wants to be our friend.

Let’s respond to him wholeheartedly by reciprocating his political embrace, and joining him on what will be an extraordinary, rollercoaster ride of world leadership.