It all reminds one of an old-fashioned cartoon. In it, an ageing, moth-eaten spinster is standing on a chair and shrieking – at the sight of a mouse. Admittedly, Donald Trump is more than a mouse but even so, the protestors’ reactions on both sides of the Atlantic are giving hysteria a bad name. We must also remember that they were the sort of protestors who thought that Reagan was an idiot. When confronted with a difficult political issue, common sense would surely dictate that the first essential is thought (then again, common sense has never been a common quality). When thinking, do not drift into fantasy. Stick to reality. The reality is that Donald Trump is the President of the United States. It follows that Her Majesty’s Government has to try hard to get on with him.

In the 1930s, an American flagship sailed into Hong Kong harbour and sent a signal to the British port admiral. “Good morning. How is the second-biggest navy in the world?” He received an instant reply. “We’re fine. How is the second best?” If only we could still respond in such jaunty terms, delegating much of our diplomacy to the Royal Navy, or to the Colonial office, But those days are over. Recessional has struck: our navies have melted away. One suspects that the new President has not read that great poem. “If, drunk with power, we loose wild tongues…” It might be worth trying, though I do not suppose that he would take any notice.

When making geo-political calculations, it is never enjoyable having to factor in British weakness. That is one reason why the rest of us often find the Europhiles so off-putting. They are never happier than when lecturing anyone who will listen about modern Britain’s diminished status. But they do have a point, damn it, even if most of them would prefer that once chastened by contemplating our insignificant future, we would crawl back to the EU and apologise. As that is not going to happen, we have to get on with other countries, principally in search of trade deals. We must do so in a world where everyone is in favour of free trade, for their own exports, and more and more countries seem interested in protection, for their own producers. If Mr Trump knew the word mercantilist he would probably express pleasant surprise that not all French ideas were bad.

The temptation to patronise Mr Trump is irresistible. After all, we have been doing that to better Americans than him for many decades. “In Washington, Lord Halifax/ Once whispered to Lord Keynes/ Its true they have the money-bags/ But we have all the brains.” But de haut en bas can be unwise. In Afghanistan and Iraq, British soldiers were too ready to assume that the Americans would be grateful for lessons on hearts and minds. After Basra and Helmand, that became less convincing. Yet Macmillan’s “Greeks to their Romans” continues to influence British thinking, though it might seem surprising that he expressed himself in such terms. A classicist and an Old Etonian, Macmillan would have known that the duties of Greek slaves in Roman households were not only clerical. When Marcus Aurelius wrote about pretty slaves, he did not mean girls. An unlucky Greek secretary might not have found it comfortable to sit at a desk.

So it might be wise to eschew history – except for congratulations on the Churchill bust – and concentrate on sucking up to President Trump. Perhaps “suck” is not the right word. Where he is concerned, there is a case for avoiding anything metaphorical and sticking to the blandest language. Yet we must get close to him and not just for trade. Any influence that we can create might prove crucial. We may have to dissuade the ape from throwing the Ming vase through the window.

It follows that we should applaud Mrs May. In fraught circumstances, she did not put a kitten heel wrong, and at least he only grabbed her hand. She was also right to offer a royal visit; there is no point in under-appeasement. There is also something sickening in the way that Leftist republicans are now pretending to come to the Queen’s defence. Her Majesty can look after herself. What her own feelings are, we can only guess. But Mr Trump is such an extraordinary fellow that even the Monarch may not be immune from a little curiosity. Who knows; a meeting might take on a Pride and Prejudice flavour and resemble one of Mr Bennet’s exchanges with The Revd Mr Collins.

There is only one point on which we can be certain. Heisenberg’s uncertainty principle has now arrived in the Oval Office. He might not be as bad as you fear, gentle reader: he might turn out to be worse. But the more alarming you find him, the more sense it makes to establish good relations with the new regime. Our PM made an excellent start.