A RARE BOOK of cartoons satirising Adolf Hitler, but officially sanctioned by the Führer himself, was sold at auction this week. On the same day, The Times reported that three internet cartoonists in Minsk who dared to ridicule Alexsandr Lukashenko, the autocratic president of Belarus, had been raided by the state security service; they were interrogated, their computers were confiscated and they now face up to five years in prison.

Here, separated by 80 years, are two dictators, each trying to control the mirth that is anathema to dictatorship. Hitler had a clunking, Austrian sense of humour, but was quite incapable of self-mockery. His decision, in 1933, to countenance this single book of mild cartoons was a subtle act of Nazi propaganda, an attempt to co-opt German humour by appearing to tolerate it. President Lukashenko has taken a blunter approach by seeking to repress political humour altogether, the surest sign of a doomed regime.

Tyrants have always feared jokes more than open protest, for the snigger is mightier than the sword. “No great movement designed to change the world can bear to be laughed at or belittled,” wrote Milan Kundera in his novel The Joke, “because laughter is the rust that corrodes everything.”

Even perfectly respectable politicians hate to be teased, as I discovered when I was parliamentary sketchwriter for this newspaper. One outraged woman MP tracked me down in the lobby to complain that what I had described as the “outfit of a 19th-century German fencing instructor” was “an Armani suit, actually”. A former fireman who became an MP was so enraged by some slight I have now forgotten that he cornered me on the stairs, shouted “Pillock” a number of times and then stormed off. Occasionally MPs would look up at the gallery and wink ingratiatingly at the sketchwriters: fish in a barrel.

Satire is the mark of a healthy democracy, the pricking of pomposity that reminds our leaders that they are not self-anointed. “Every joke is a tiny revolution,” thought George Orwell. “Whatever destroys dignity, and brings down the mighty from their seats, preferably with a bump, is funny.”

Every politician craves gravitas, but the more extreme the politics, the more crucial dignity becomes, for laughter leaves the emperor with no clothes. This is equally true for terrorists. Osama bin Laden has become a staple of playground humour. Within hours of 9/11 and 7/7, the jokes, tasteless and defiant, began to emerge, the natural response to the oppression of terror, a tiny revolution against fear.

Tyrants and terrorists try to elevate themselves above humour. In 1933, Hitler might tolerate some carefully orchestrated ribbing, but once war was under way Goebbels declared that “humour has its limits”: anti-Nazi jokes became punishable by death in Germany, just as they flourished outside it. Every British playground rang to the singing of “Hitler, has only got one ball, Goering has two, but very, very small . . .”

In North Korea, satire is banned for the simple reason that since the Communist state is officially perfect, there is officially nothing to satirise. Only the Dear Leader, Kim Jong Il, is permitted to make jokes. Here is an example: “To expect victory in the revolution without the leader is as good as to expect a flower to bloom without the sun.”

You may need a moment to recover from that, but wait, here comes another. When he goes jet-skiing with his officials, Kim arranges that one of the jetskis has insufficient petrol to get back, leaving its driver marooned at sea. Hilarious.

The first sign that a tyrant’s days are numbered comes not with the sound of gunfire, but the gentle ripple of disrespectful laughter. Before the French Revolution, the monarchy was comprehensively undermined by satire, ribald and unrelenting. Recall Nicolae Ceausescu’s furious disbelief when he finally realised the crowds of Romanians below the presidential balcony were laughing at him.

Jokes evolve spontaneously in the wake of despotism: when Mobutu Sésé Seko, former President of Zaire and arch kleptocrat, finally died of prostate cancer (in an expensive French hospital), his people began referring to their highest denomination banknote as “a prostate”. Within hours of the unsuccessful attempt to bomb Saddam Hussein during Operation Shock and Awe, this joke was already doing the rounds of the Baghdad cafés: Following the attack, the Iraqi Information Minister has summoned all Saddam’s body-doubles to a meeting to tell them: “The good news is that our beloved leader has survived, so you all still have jobs. The bad news is that he has lost an arm.”

Saddam watched his own downfall on television from his bunker: the end came not with the footage of US air strikes, but the sight of his oppressed people, ridiculing him in the street.

A rich vein of anti-authoritarian humour secretly flourished under communism, mocking the great chasm between between promised liberty and the reality of repression. There is really only one, infinitely adaptable joke in anti-tyrant humour, illustrating the distance between the leader’s grandiose pretensions and public perception, the joke-teller and his listeners conspiring in disdain for the absurdity of the system. The cartoons banned by President Lukashenko precisely fit this pattern: the President looking formal and powerful, but with floppy ears, a fox’s snout or a prison uniform.

A man goes into the post office and complains: “These new Lenin stamps don’t stick properly.”

“That, comrade, is because you are spitting on the wrong side.”

At any point in modern history, “Lenin” might be replaced with Stalin, Khrushchev, Castro, Saddam, Ceausescu, and any number of South American and African despots. Doubtless a version of this joke is now doing the rounds in Minsk. Perhaps even in North Korea, if we could only hear it, the Dear Leader is the butt of the stamp joke, the whispered harbinger of democracy.

Join the Debate
Send your e-mails via www.timesonline.co.uk/debate

Times Recommends

• Bank charges hit us for being human
• Sorry, Father, thou still shalt not steal
• The shed where Santa’s failures go to die