Howard Jacobson: Get your tailoring right, and you can set out to solve the world's problems

How does he get that dimple in his tie? Obama, I mean. Who else? Obama the beautiful. Obama the sonorous. Obama the Messiah.

I don't make a habit of admiring people younger than me, unless they are of another time and long dead, in which case their anteriority makes them older. You can love someone younger – for love is part protectiveness – but it is not seemly to admire them. That way dotage lies. The trouble is that after a certain age there isn't anybody older than yourself left standing. So Obama it is. He'll be pleased to know he enjoys my esteem.

In fact I know how he gets that dimple in his tie. He ties it by a method known as the four-in-hand, a phrase that might have something to do with the horse-drawn vehicle of that name. Maybe it describes the way coachmen tied their cravats or hitched their reins. Whatever the etymology I am taken with the effect, and spent most of last week following instructions on how to achieve it on YouTube. You start with the wide end ("W") of your tie on the right, then cross it over the narrow end ("N"), ensuring that "W" is kept about a foot longer than "N". Then you...

It was only when I'd completely mastered the four-in-hand, holding a mirror to my computer and getting my wife to check me over every step of the way, that I realised I was being taught how to tie a tie in the way I have always tied a tie. Only I can't get the Obama dimple. The narrowness of the knot, yes. The insolent asymmetry of the knot, yes. But not the dimple in "W" just below the knot.

It still isn't clear how he manages it, but I suspect the secret lies in hauling the tie tight into the hot V-shaped hollow of your collar, and for that you need exactly the right spread of collar – not English Bufton-tufton cut-away, and not with the points limp and close together in the manner of mafiosi and art dealers. It goes without saying that you also need exactly the right amount of neck. Too little and you concertina the collar (think Cameron), too big and the dimple is lost in pleats of flesh (think Kenneth Clarke).

Here again Obama is perfection. The neck slender, but not wasted. The shirt white. (Only a fool wears a shirt of any other colour and only a scoundrel wears stripes.) The suit black, two buttoned, with long lapels. And thus tailored he will set about solving the problems of the world. Don't laugh. I attach immense significance to the tailoring of Messiahs. There lingers in the British psyche – particularly the left side of it – a sentimental belief that political conviction must come in an untidy package. Michael Foot overdid it even for a socialist, but there remains an ideological association of dishevelment with truth. You can't go on a march in a black suit bought from Hartmax in Chicago and a dimple in your tie. You can't go on a march in a tie full stop. And there, reader, is the rub.

I measure a man's seriousness by the degree of moral ambivalence he is able to intimate in his appearance. Here is surface, the subtle politician and thinker says, here is my homage to gorgeousness, worldliness and good manners, but don't suppose I do not have that within that passeth show.

Too much attention to exterior show and the man is trivial; too little and he is a fanatic. The person who cannot smile urbanely even when the world is falling apart is no better than the person who can do nothing else. And those who think they prove their integrity by looking shabby by the standards of their own society, or by adopting the dress of the oppressed (as though the oppressed are a model by virtue of their oppression), only demonstrate the narrowness of their sympathies.

Showing just the right amount of white shirt cuff – inviting them to tea, as it were, in the Oval Office – Obama addressed the world's political villains – "We will extend a hand, if you are willing to unclench a fist." The metaphor is good. In the midst of war it reinstates the civilities. I'll dimple my tie, you dimple yours, and we will talk it over. But it contains the necessary threat within the wit as well, for if they don't unclench their fists...

Well, we shall see. In the meantime, in the far less sophisticated moral world we call our own country, the intellectually challenged who staff our universities are down on their knees kissing every clenched fist that will consent to their sycophancy. Take as an example plucked at random – trust me, reader, it just fell to hand – the letter written to The Guardian last week, demanding that Israel lose. Not withdraw, not seek a truce, not radically change its thinking – as many of us wish – but lose. Lose to the clenched fist of Hamas.

It was signed by those who exist to sign such things – professors of Media and Communications, lecturers in Visual Cultures and Gender Studies (gender studies and Hamas: get that!), boycotters, sandal-wearers, banner wavers, professionally ashamed Jews. As an exercise in simple-mindedness – what else do universities teach now? – it could hardly be excelled.

Israel had been waging war against the Palestinians for 60 years it said, omitting to mention the war that Arab armies had been waging against Israel, 60 years ago promising "a war of extermination" – extermination, note, not a two-state solution – culminating in the joyous prospect of "feeding the fish of the Mediterranean with the bones of Jews". (Imagine starting a history of the Second World War with the bombing of Dresden and you have the picture.) Thus decontextualised, Israel, the letter continued, must now accept that its security depends on "peaceful co-existence with its neighbours". Gosh, why hasn't anyone thought of that before. Peaceful co-existence. You hear that, Mr Obama?

There is no monopoly on compassion. Signing a letter doesn't make you a humanitarian. I too don't want to see another dead Palestinian child. Not a one. But peace won't come just because, ignored and impotent in your campuses of moral simplicity, with only the young and the like-minded to address, you wish for it.

Regard Obama. You have to work at truth. What seems isn't always what is. And what will be waits on more than the velleities of the ill-informed. In the taut and intricate resolution of Obama's dimpled tie is our most realistic hope for peace.

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